Biomedical subjects

T Ohama

Publications and source records attributed to T Ohama.

At least 19 recordsLinked to original sources

PubMed2006

Role of TNF-alpha in muscularis inflammation and motility disorder in a TNBS-induced colitis model: clues from TNF-alpha-deficient mice.

Macroscopic and histological analysis revealed that the colonic inflammation induced by 2,4,6-trinitrobenzenesulphonic acid (TNBS) was of lower grade in tumour necrosis factor-alpha (TNF-alpha)(-/-) mice than in wild-type mice. Myeloperoxidase activity, an indicator of neutrophilic infiltration, was also low in both the mucosal and smooth muscle layer of the TNF-alpha(-/-) mouse colon. After the induction of inflammation with TNBS, the levels of proinflammatory cytokines, such as TNF-alpha, interleukin-1beta and interleukin-6, were elevated both in the inflamed mucosa and muscle layers in the wild-type mice; however, the productions of these cytokines were greatly reduced in the TNF-alpha(-/-) mouse colon. The contractions of isolated colonic smooth muscle strips induced by several stimulatory agents were significantly decreased after treatment with TNBS in wild-type mice; however, these contractions were scarcely affected in TNF-alpha(-/-) mice. Finally, using the organ culture method, we found that TNF-alpha directly (independent of mucosal inflammation) disturbs the smooth muscle function. These results suggest that TNF-alpha plays an essential role not only in mucosal inflammation but also in muscularis inflammation in the colon of mice with TNBS-induced colitis, and that TNF-alpha directly induces motor dysfunctions by acting on the smooth muscle.

Animals↗

PubMed2003

[Congenital tracheal stenosis due to complete cartilage rings with right pulmonary agenesis].

A 2-month-old male infant with severe dyspnea was diagnosed as having right pulmonary agenesis at birth and was admitted to our hospital after tracheal intubation with an endotracheal tube of 3 mm in diameter. However, the trachea was too stenotic to place the tube in the proper position. Chest X-ray on admission showed pneumonia of the left lung. Preoperative chest computed tomography (CT) scan and bronchoscopy showed that from the level of 12 mm beneath the coricoid cartilage, the trachea tapered and continuing to the tracheal carina and that the smallest tracheal level was located 18 mm distal from the coricoid cartilage, the area of which was 4 mm2. His respiratory condition rapidly deteriorated in spite of intravenous administration of antibiotics and mechanical ventilation. Percutaneous cardiopulmonary support (PCPS) was used to maintain his pulmonary function, and pericardial tracheoplasty was performed. Chest X-ray immediately after the operation did not show left lung reexpansion due to severe pulmonary edema. High-dose steroid pulse therapy was performed, but it was not effective. He died from acute respiratory failure due to infantile respiratory distress syndrome (IRDS) on postoperative day 3. The outcome in this case shows that it is very risky to repair tracheal stenosis in a patient with pneumonia using PCPS.

Cardiopulmonary Bypass↗

PubMed2001

ATP-binding cassette transporter-1 induces rearrangement of actin cytoskeletons possibly through Cdc42/N-WASP.

Positional cloning approaches revealed that Tangier disease (TD), a genetic high density lipoprotein deficiency, is associated with mutations in the ATP-binding cassette transporter-1 (ABCA1) gene. However, the biological function of ABCA1 is still not fully investigated. Recently, we have reported that the cells from the patients with TD had abnormal actin cytoskeletons in association with decreased expression of Cdc42, a member of RhoGTPases family. In the present study, we have found that actin cytoskeletons were altered in HEK293 cells transfected with human ABCA1 (hABCA1) cDNA. Cells expressing hABCA1 were divided into the following two groups by the distinct morphology with altered actin cytoskeletons: one had increased formation of filopodia (designated as Type I) and the other had long protrusions (designated as Type II). Type I cells had morphology similar to that of cells transfected with dominant active form of Cdc42 (Cdc42-DA, V12Cdc42Hs-DA). Type II cells had morphology similar to that of cells transfected with neural Wiskott-Aldrich Syndrome Protein (N-WASP),one of the established downstream effector molecules of Cdc42. We have obtained the data showing a possible pathway of ABCA1/Cdc42/N-WASP by the following experiments. Introduction of mutant of Cdc42 (dominant negative form of Cdc42, N17Cdc42Hs-DN) and N-WASP (N-WASP lacking verprolin homology domain, N-WASPDeltaVPH), both of which are supposed to have potential to inhibit rearrangement of actin cytoskeletons, significantly inhibited the morphological changes induced by expression of hABCA1. Immunoprecipitation study with FLAG-tagged ABCA1 (hABCA1-FLAG) revealed that Cdc42 was coimmunoprecipitated with hABCA1-FLAG. In addition, we have demonstrated possible intracellular colocalization of these two molecules in the overexpressing cells by the confocal laser microscopy. These results may suggest that hABCA1 regulates actin organization through the possible interaction with Cdc42Hs.

ATP Binding Cassette Transporter 1↗

PubMed2001

Vascular endothelial dysfunction resulting from L-arginine deficiency in a patient with lysinuric protein intolerance.

Although L-arginine is the only substrate for nitric oxide (NO) production, no studies have yet been reported on the effect of an L-arginine deficiency on vascular function in humans. Lysinuric protein intolerance (LPI) is a rare autosomal recessive defect of dibasic amino acid transport caused by mutations in the SLC7A7 gene, resulting in an L-arginine deficiency. Vascular endothelial function was examined in an LPI patient who was shown to be a compound heterozygote for two mutations in the gene (5.3-kbp Alu-mediated deletion, IVS3+1G-->A). The lumen diameter of the brachial artery was measured in this patient and in healthy controls at rest, during reactive hyperemia (endothelium-dependent vasodilation [EDV]), and after sublingual nitroglycerin administration (endothelium-independent vasodilation [EIV]) using ultrasonography. Both EDV and NO(x) concentrations were markedly reduced in the patient compared with those for the controls. They became normal after an L-arginine infusion. EIV was not significantly different between the patient and controls. Positron emission tomography of the heart and a treadmill test revealed ischemic changes in the patient, which were improved by the L-arginine infusion. Thus, in the LPI patient, L-arginine deficiency caused vascular endothelial dysfunction via a decrease in NO production.

Adult↗

PubMed2000

Distribution of cognates of group II introns detected in mitochondrial cox1 genes of a diatom and a haptophyte.

We identified group IIA introns that contain an open reading frame (ORF) in the mitochondrial cytochrome oxidase subunit I (cox1) genes of yellow algae, a diatom Thalassiosira (Th.) nordenskioeldii CCMP 992 collected from the east coast of USA, and a haptophyte Pavlova (Pa.) lutheri CCMP 1325 collected from Finland. Cognate introns of CCMP 1325 were detected in all Pa. lutheri strains investigated, which were collected from various oceans. In contrast, the intron was absent from closely related species belonging to the same genus Pavlova. This was also the case for the group II intron detected in a diatom Th. nordenskioeldii CCMP 992. The group II intron of CCMP 992 was located at the corresponding site to the group IIA intron found in Pylaiella (synonym, Pilayella) littoralis. The deduced secondary structures of these introns, one of which is from a diatom and the other from a brown alga, were virtually identical. In contrast, the haptophyte group II intron was inserted at a novel locus, and shares no particularly high sequence homology with any intron known to date. The phylogenetic tree based on the intronic ORF domain was not congruent with that based on the cox1 exon. The most prominent property of the intronic ORF tree was that introns located at homologous sites made robust pair clades irrespective of the phylogenetic relationships of the organisms. This suggests that mitochondrial group II introns often invade intronless alleles across the species barrier with site specificity. Homology analysis of the haptophyte intronic ORF suggested that it comprises three domains: reverse transcriptase (RT), RNA maturase (Ma), and H-N-H endonuclease. However, the intronic ORF of the diatom contains the Ma domain but is apparently missing the H-N-H domain, and its RT domain is most probably partly or completely lacking in function.

Amino Acid Sequence↗

PubMed2000

Phylogenetic analysis of diatom coxI genes and implications of a fluctuating GC content on mitochondrial genetic code evolution.

In order to address the relationships among diatom groups and to investigate possible changes in their mitochondrial (mt) genetic codes, we have analyzed a 1.1-kb region of the cytochrome c oxidase subunit I (coxI) gene from eight diverse diatom species. A phylogenetic analysis of these coxI sequences including representative species of the Phaeophyta, Xanthophyta, Eustigmatophyta and Haptophyta showed that the diatoms (Bacillariophyta) formed a well-supported monophyletic group. Of the eight species investigated, four have been classified together as radial centric diatoms based on morphology. However, in our coxI tree, the two radial centrics belonging to the order Thlassiosirales (Skeletonema costatum and Thalassiosira nordenskioldii) were placed as the sister group to the multipolar centric diatoms, while the other two radial centrics (Melosira ambigua and Rhizosolenia setigera) were in another clade. Also, in two species of the Tharassiosirales we found UGA codons that occur at conserved tryptophan (Trp) sites in the coxI sequences, strongly indicating that UGA codes for Trp in these diatoms. No evidence of a deviant genetic code was detected in the other analyzed diatom species. There was no apparent relationship between the nucleotide third-position GC content of mtDNA (based on the sequenced coxI region) and the presence of a deviant genetic code.

Base Composition↗

PubMed2000

Evolutionary relationship between dinoflagellates bearing obligate diatom endosymbionts: insight into tertiary endosymbiosis.

The marine dinoflagellates Peridinium balticum and Peridinium foliaceum are known for bearing diatom endosymbionts instead of peridinin-containing plastids. While evidence clearly indicates that their endosymbionts are closely related, the relationship between the host dinoflagellate cells is not settled. To examine the relationship of the two dinoflagellates, the DNA sequences of nuclear small-subunit rRNA genes (SSU rDNA) from Peridinium balticum, Peridinium foliaceum and one other peridinin-containing species, Peridinium bipes, were amplified, cloned and sequenced. While phylogenetic analyses under simple models of nucleotide substitution weakly support the monophyly of Peridinium balticum and Peridinium foliaceum, analyses under more sophisticated models significantly increased the statistical support for this relationship. Combining these results with the similarity between the two endosymbionts, it is concluded that (i) the two hosts have the closest sister relationship among dinoflagellates tested, (ii) the hypothesis that the diatom endosymbiosis occurred prior to the separation of the host cells is most likely to explain their evolutionary histories, and (iii) phylogenetic inferences under complex nucleotide evolution models seem to be able to compensate significant rate variation in the two SSU rDNA.

Animals↗

PubMed1998

Distinctive origins of group I introns found in the COXI genes of three gree algae.

Upon surveying the cytochrome c oxidase subunit I (COXI) gene of green algae, we found group I introns in three species of algae, Chlorella vulgaris (Cv), Scenedesmus quadricauda (Sq) and Protosiphon botryoides (Pb). The comparative analysis of these nucleotide sequences and their secondary structures revealed that the introns of Cv, Sq, and Pb belong to groups IB1, ID, and IB2, respectively. Each of the three introns contained an open reading frame (ORF) that showed a similarity to the sequence of the LAGLIDADG endonuclease family. However, each of the intronic ORFs in Sq and Pb had a discontinuity in the middle of' the sequences coding for the LAGLIDADG endonuclease. Either of the two ORFs could be restored to a sequence homologous to the LAGLIDADG endonuclease by the insertion of a nucleotide in the appropriate position. In Sq, a putative pseudo-knot structure was detected in the intronic ORF This suggests the occurrence of a ribosomal frameshift in the translation of the ORF. because such pseudo-knot structures are common in viral ORFs employing a (-1) ribosomal frameshift. In the phylogenetic tree that was inferred from the amino acid sequences of algal and non-algal intronic ORFs, the three algal ORFs did not make a cluster, but were scattered throughout the tree. In addition. each of the three algal ORFs showed a close relationship to the ORFs of non-algal introns that were inserted at the corresponding site of the COX] gene, suggesting distinctive origins of the three algal introns via independent horizontal transfers.

Amino Acid Sequence↗

PubMed1998

Directionally evolving genetic code: the UGA codon from stop to tryptophan in mitochondria.

For the comprehensive analyses of deviant codes in protistan mitochondria (mt), we sequenced about a 1.1-kb region of a mitochondrial (mt) gene, the cytochrome c oxidase subunit I (coxI) in two chlorarachniophytes, the filose amoeba Euglypha rotunda, the cryptomonad Cryptomonas ovata, the prymnesiophyte (haptophyte) Diacronema vlkianum (Pavlovales), and the diatom Melosira ambigua. As a result of this analysis, we noticed that the UGA codon is assigned to tryptophan (Trp) instead of being a signal for translational termination in two chlorarachniophytes and in E. rotunda. The same type of deviant code was reported previously in animals, fungi, ciliates, kinetoplastids, Chondrus crispus (a red alga), Acanthamoeba castellanii (an amoeboid protozoon), and three of the four prymnesiophyte orders with the exception of the Pavlovales. A phylogenetic analysis based on the COXI sequences of 56 eukaryotes indicated that the organisms bearing the modified code, UGA for Trp, are not monophyletic. Based on these studies, we propose that the ancestral mitochondrion was bearing the universal genetic code and subsequently reassigned the codon to Trp independently, at least in the lineage of ciliates, kinetoplastids, rhodophytes, prymnesiophytes, and fungi. We also discuss how this codon was directionally captured by Trp tRNA.

Amoeba↗

PubMed1997

Selenocysteine tRNA[Ser]Sec levels and selenium-dependent glutathione peroxidase activity in mouse embryonic stem cells heterozygous for a targeted mutation in the tRNA[Ser]Sec gene.

To investigate the effect of a reduced level of selenocysteine (Sec) tRNA[Ser]Sec in selenoprotein biosynthesis, two mouse embryonic stem (ES) cell lines heterozygous for the corresponding gene were generated by homologous recombination of the host genome with targeting vectors encoding a deleted or a disrupted tRNA[Ser]Sec gene. The presence of a single functional gene in ES cells afforded us an opportunity to determine directly in the cell line the effect of reduced gene dosage on (1) the levels of the Sec tRNA[Ser]Sec population, (2) the distributions of the isoacceptors within the Sec tRNA population, and (3) selenoprotein biosynthesis. We therefore determined the amounts and distributions of the two major tRNA[Ser]Sec isoacceptors, designated mcm5U and mcm5Um, within the Sec tRNA population and determined the activity of the anti-oxidant, selenium-containing glutathione peroxidase (GPx) in the heterozygotes and in wild type cells grown in media with and without added selenium. The level of the Sec tRNA[Ser]Sec population in the heterozygotes was approximately 60% of that of wild type cells grown in media under normal conditions, while the ratio of the mcmU isoacceptor in wild type vs mutant cells was approximately 2:1 and of the mcmUm isoacceptor approximately 1:1. In the presence of media supplemented with selenium, the Sec tRNA[Ser]Sec population increased about 20% in wild type cells and virtually not all in heterozygous cells, and the level of the Sec tRNA[Ser]Sec population was, therefore, approximately 50% of that of wild type cells. GPx activity was indistinguishable among these cell lines in either selenium-supplemented or unsupplemented media, indicating that the resultant changes in tRNA[Ser]Sec levels did not have a measurable effect on GPx biosynthesis.

Animals↗

PubMed1997

Use of a deviant mitochondrial genetic code in yellow-green algae as a landmark for segregating members within the phylum.

Several algae that were previously classified in the phylum Xanthophyta (yellow-green algae) were assigned in 1971 to a new phylum, Eustigmatophyta. It was anticipated that the number of algae reclassified to Eustigmatophyta would increase. However, due to the fact that the morphological characteristics that segregate eustigmatophytes from other closely related algae can be only obtained through laborious electron microscopic techniques, the number of members in this phylum have increased rather slowly. We attempted, therefore, to segregate two closely related groups of algae, eustigmatophytes and yellow-green algae, on the basis of a molecular phylogenetic tree as a means of providing an alternative method of distinguishing these phyla. We analyzed the mitochondrial cytochrome oxidase subunit I (COXI) gene sequences of eight algae classified as xanthophyceans and found that six manifested the expected deviant genetic code where AUA codes for methionine (AUA/Met), but not for isoleucine (AUA/Ile) as in the universal genetic code. The other two, Monodus sp. (CCMP 505) and Ophiocytium majus (CCAP 855/1), which were presumed to be yellow-green algae, and all the examined eustigmatophytes utilized AUA for Ile. In addition, the phylogenetic tree of COXI gene sequences showed that the six yellow-green algae bearing the AUA/Met deviant code composed a tight clade with a bootstrap value of 100%. The phylogenetic tree of the corresponding sequences from Monodus sp. and Ophiocytium majus and the eustigmatophytes also composed a tight cluster, but with a bootstrap value of 92%. These results strongly suggest that two previously classified members of yellow-green algae belong to the phylum Eustigmatophyta. Therefore, examination of the mitochondrial genetic code in algae appears to be a potentially very useful genetic marker for classifying these organisms, especially when it is considered with the results obtained through a molecular phylogenetic tree.

DNA, Mitochondrial↗

PubMed1997

Algae or protozoa: phylogenetic position of euglenophytes and dinoflagellates as inferred from mitochondrial sequences.

The chloroplasts of euglenophytes and dinoflagellates have been suggested to be the vestiges of endosymbiotic algae acquired during the process of evolution. However, the evolutionary positions of these organisms are still inconclusive, and they have been tentatively classified as both algae and protozoa. A representative gene of the mitochondrial genome, cytochrome oxidase subunit I (coxI), was chosen and sequenced to clarify the phylogenetic positions of four dinoflagellates, two euglenophytes and one apicomplexan protist. This is the first report of mitochondrial DNA sequences for dinoflagellates and euglenophytes. Our COXI tree shows clearly that dinoflagellates are closely linked to apicomplexan parasites but not with algae. Euglenophytes and algae appear to be only remotely related, with euglenophytes sharing a possible evolutionary link with kinetoplastids. The COXI tree is in general agreement with the tree based on the nuclear encoded small subunit of ribosomal RNA (SSU rRNA) genes, but conflicts with that based on plastid genes. These results support the interpretation that chloroplasts present in euglenophytes and dinoflagellates were captured from algae through endosymbioses, while their mitochondria were inherited from the host cell. We suggest that dinoflagellates and euglenophytes were originally heterotrophic protists and that their chloroplasts are remnants of endosymbiotic algae.

Animals↗

PubMed1997

A deviant mitochondrial genetic code in prymnesiophytes (yellow-algae): UGA codon for tryptophan.

The sequence of a representative mitochondrial gene COXI, encoding cytochrome c oxidase subunit I, was determined in five species that cover all the orders of the Prymnesiophyta with the exception of the Pavlovales. Through this analysis, we noticed that the 'stop' codon UGA appears frequently and, specifically, at conserved tryptophan (Trp) sites of the gene. We showed these sites were not edited in the corresponding mRNA in one of these species, Isochrysis galbana. Therefore, it is most likely that the UGA codon is used for Trp, and not as a stop codon, in prymnesiophytes. All the analyzed prymnesiophytes made a tight cluster on the COXI phylogenetic tree which includes representative species of green-algae, land plants, yellow-green algae, eustigmatophytes and a red-alga. This suggests a monophyletic origin for the prymnesiophytes. The same deviant genetic code, i.e. UGA for Trp, has also been found in the red-alga, Chondrus crispus. In spite of the fact that this red-alga and the prymnesiophytes, share the same deviant genetic code for Trp, close affinity between the two groups was not statistically supported by the phylogenetic analysis of COXI sequences.

Base Sequence↗

PubMed1997

Planarian mitochondria sequence heterogeneity: relationships between the type of cytochrome c oxidase subunit I gene sequence, karyotype and genital organ.

Freshwater planarians Dugesia japonica from three localities were examined for cytochrome c oxidase subunit I (COI) gene sequence, karyotype and the presence of genital organ. The planarians from Mt Fujiwara in Japan were composed of two different groups; one revealed inter- and intraindividual COI gene heterogeneity, while another revealed no sequence heterogeneity. The sequence in planarians from Mt Alishan in Taiwan was homogeneous, while that from the Kenting National Park in Taiwan revealed a considerable heterogeneity. All the planarians having the homogeneous gene sequences carry the 2X karyotype and many of them had genital organs. These are assumed to belong to the sexual lineage. In contrast, almost all planarians having heterogeneous sequences carry the karyotype of either 3X plus 2X (mixoploid) or 3X, and all of them lack genital organs. These lineages are assumed to be asexual. The heterogeneity of COI gene sequences in the presumed asexual lineages would have resulted from an accumulation of mutations by repeated asexual reproduction.

Animals↗

PubMed1996

Phylogenetic relationships and evolution of the Japanese Carabinae ground beetles based on mitochondrial ND5 gene sequences.

The phylogenetic relationships of the Japanese Carabinae ground beetles were analyzed by comparing 1,069 nucleotide sequences in the mitochondrial gene encoding NADH dehydrogenase subunit 5 (ND5). The ND5 phylogenetic tree revealed that the hind-wingless Carabina and the hind-winged Calosoma/Campalita (Calosomina) diverged from the common ancestor, and Cychrus (Cychrini) is the outgroup of them. Five distinct clusters (groups) can be recognized in the Carabina, i.e., CARABUS, HEMICARABUS, LEPTOCARABUS, APOTOMOPTERUS, and PROCRUSTES/DAMASTER. The ancestors of these lineages diverged almost at the same time more than 10 Myr ago. The Carabus cluster includes two subclusters, Carabus and Ohomopterus. Two species of Carabus examined are phylogenetically rather remote, while five species among Ohomopterus are closely related to each other. The results suggest that diversification of Carabus started much earlier than that of Ohomopterus, presumably in the Eurasian continent, and that of Ohomopterus in the Japanese archipelago. The branching order in the LEPTOCARABUS lineage was established, Authenocarabus/Pentacarabus being their outgroup. In the DAMASTER/PROCRUSTES lineage, Procrustes is placed as the outgroup of Damaster, with the branching order of Coptolabrus and Acoptolabrus/Damaster. The diversification of the Damaster subspecies appeared to have occurred in the Japanese archipelago earlier than Ohomopterus, and its phylogeny reflects their geographic distribution in the archipelago rather than the morphological characters.

Animals↗

PubMed1996

Parallel evolution in radiation of Ohomopterus ground beetles inferred from mitochondrial ND5 gene sequences.

Molecular phylogenetic analyses using mitochondrial NADH dehydrogenase subunit 5 (ND5) gene sequences representing all 15 species and the majority of subspecies or races of the Ohomopterus ground beetles from all over the Japanese archipelago have uncovered a remarkable evolutionary history. Clustering of the species in the molecular phylogenetic tree is linked to their geographic distribution and does not correlate with morphological characters. Taxonomically the "same" species or the members belonging to the same species-group fall out in more than two different places on the ND5 tree. Evidence has been presented against a possible participation of ancestral polymorphism and random lineage sorting or of hybrid individuals for the observed distribution of mitochondrial DNA haplotypes. The most plausible explanation of our results is that parallel evolution took place in different lineages. Most notably, O. dehaanii, O. yaconinus, and O. japonicus in a lineage reveal almost identical morphology with those of the "same" species (or subspecies) but belonging to the phylogenetically remote lineages.

Animals↗

PubMed1996

UAG is a sense codon in several chlorophycean mitochondria.

The mitochondrial genetic code of those land plants and green algae that have been examined does not deviate from the universal one. A red alga, Chondrus crispus, is the sole reported example throughout the algae that uses a deviant (non-universal) mitochondrial genetic code (UGA=Trp). We have analyzed 366-bp DNA sequences of the gene for mitochondrial cytochrome oxidase subunit I (COXI) from ten chlorophyceaen algae, and detected 3-8 in-frame UAG codons in the sequences of five species. Comparisons of these sequences with those of other algae and land plants have shown that most of the UAG sites in Hydrodictyon reticulatum, Pediastrum boryanum and Tetraedron bitridens correspond to alanine, and those of Coelastrum microporum and Scenedesmus quadricauda to leucine. The three species in which UAG probably codes for alanine are characterized by zoospore formation in asexual reproduction and form a clade in the COXI phylogenetic tree. The two species in which UAG codes for leucine are known to form daughter coenobia and pair in the tree. This is the first report on a deviant mitochondrial genetic code in green algae. Mutational change(s) in the release factor corresponding to UAG would be involved in these code changes. No genetic code deviation has been found in five other species examined.

Alanine↗

PubMed1995

Translation of synonymous codons in family boxes by Mycoplasma capricolum tRNAs with unmodified uridine or adenosine at the first anticodon position.

In Myocoplasma capricolum, codon family boxes except for arginine and threonine (CUN leucine, GUN valine, UCN serine, CCN proline, GCN alanine, and GGN glycine) have only a single tRNA species with the anticodon sequence UNN (N is U, C, A or G), the first nucleoside U being unmodified. Incorporation of the [3H]amino acid into the peptide fraction was examined with the M. capricolum cell-free translation system. Synthetic mRNA containing each of the respective amino acid codons in the coding frame was subjected to translation. The tRNAUNN translated all the family box codons with similar, if not equal, efficiencies. In M. capricolum, there are two species of threonine tRNA, tRNA(UGUThr) and tRNA(AGUThr), the first nucleoside U or A being unmodified. The tRNA(UGUThr) species translates codons ACA, ACG and ACU efficiently, and ACC only poorly. In contrast, the tRNA(AGUThr) species translates codons ACU, ACC and ACG efficiently and ACA poorly.

Adenosine↗