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PubMed2000

Estimation of synteny conservation and genome compaction between pufferfish (Fugu) and human.

BACKGROUND: Knowledge of the amount of gene order and synteny conservation between two species gives insights to the extent and mechanisms of divergence. The vertebrate Fugu rubripes (pufferfish) has a small genome with little repetitive sequence which makes it attractive as a model genome. Genome compaction and synteny conservation between human and Fugu were studied using data from public databases. METHODS: Intron length and map positions of human and Fugu orthologues were compared to analyse relative genome compaction and synteny conservation respectively. The divergence of these two genomes by genome rearrangement was simulated and the results were compared to the real data. RESULTS: Analysis of 199 introns in 22 orthologous genes showed an eight-fold average size reduction in Fugu, consistent with the ratio of total genome sizes. There was no consistent pattern relating the size reduction in individual introns or genes to gene base composition in either species. For genes that are neighbours in Fugu (genes from the same cosmid or GenBank entry), 40-50% have conserved synteny with a human chromosome. This figure may be underestimated by as much as two-fold, due to problems caused by incomplete human genome sequence data and the existence of dispersed gene families. Some genes that are neighbours in Fugu have human orthologues that are several megabases and tens of genes apart. This is probably caused by small inversions or other intrachromosomal rearrangements. CONCLUSIONS: Comparison of observed data to computer simulations suggests that 4000-16 000 chromosomal rearrangements have occurred since Fugu and human shared a common ancestor, implying a faster rate of rearrangement than seen in human/mouse comparisons.

Animals↗
PubMed1998

The identification and characterization of microsatellites in the compact genome of the Japanese pufferfish, Fugu rubripes: perspectives in functional and comparative genomic analyses.

Fugu rubripes (Fugu) has one of the smallest recorded vertebrate genomes and is an economic tool for comparative DNA sequence analysis. Initial characterization of 128 kb of Fugu DNA attributed the compactness of this genome, in part, to a sparseness of repetitive DNA sequence compared with mammalian genomic sequences. This paper describes a new and comprehensive analysis in which 501 theoretically possible microsatellites with a repeat unit of one to six bases were used to query two orders of magnitude more Fugu DNA (i.e. 11.338 Mb). A total of 6042 microsatellites were identified and categorized. In decreasing order, the 20 most frequently occurring microsatellites are AC, A, C, AGG, AG, AGC, AAT, AAAT, ACAG, ACGC, ATCC, AAC, ATC, AGGG, AAAG, AAG, AAAC, AT, CCG and TTAGGG. The 20 most frequently occurring microsatellites represent 81.79% of all microsatellites identified. Our results indicate that one microsatellite occurs every 1.876 kb of DNA in Fugu, 11.55% of the microsatellites are detected in open reading frames that are predicted protein coding regions. With respect to the proportion of microsatellites present in open reading frames and the total abundance (bp) of all microsatellites, the genome of Fugu is similar to the genome of many other vertebrate species. Previous estimates performed indicate that approximately 1% of many vertebrate genomes are comprized of microsatellite sequences. However, many differences prevail in the abundance and frequency of the individual microsatellite classes. Many of the frequently occurring microsatellites in Fugu are known to code in other species for regions in proteins such as transcription factors, whilst others are associated with known functions, such as transcription factor binding sites and form part of promoter regions in DNA sequences of genes. Therefore, it is likely that such repeats in genomes have a role in the evolution of genes, regulation of gene expression and consequently the evolution of species.

Animals↗
PubMed2004

Characterisation and expression analysis of interleukin 2 (IL-2) and IL-21 homologues in the Japanese pufferfish, Fugu rubripes, following their discovery by synteny.

This investigation provides the first conclusive evidence for the existence of the interleukin 2 (IL-2) and IL-21 genes in bony fish. The IL-2 and IL-21 sequences have been determined in Fugu rubripes by exploiting the conservation of synteny that is found between regions of the human and Fugu genomes. The predicted 149-amino acid IL-2 homologue contains the IL-2 family signature, has a predicted secondary structure of three alpha helixes and has the two cysteines important in disulphide-bond formation. It shows low amino acid identities (24-34%) with other known IL-2 sequences. The predicted 155-amino acid IL-21 homologue has a predicted secondary structure of four alpha helixes and has the four cysteines important in disulphide-bond formation. It shows low amino acid identities (29-31%) with other known IL-21 sequences. The gene organisation of Fugu IL-2 and IL-21 and the level of synteny between the human and Fugu genomes has been well conserved during evolution, with the order and orientation of the genes matching exactly to human Chromosome 4. Phytohaemagglutinin stimulation of Fugu kidney cells resulted in a large increase in the Fugu IL-2 and IL-21 transcripts. In vivo stimulation of Fugu with LPS and poly I:C showed IL-21 expression to be localised within mucosal tissues. The discovery of IL-2 and IL-21 in fish will now allow more detailed investigations into T-helper cell responses.

Amino Acid Sequence↗
PubMed2005

Characterisation and expression analysis of an interleukin 6 homologue in the Japanese pufferfish, Fugu rubripes.

The first IL-6 sequence in fish has been determined in Fugu rubripes by exploiting the synteny that is found between some regions of the human and Fugu genomes. The predicted 227 aa IL-6 homologue contains the IL-6/G-CSF/MGF motif, has a predicted secondary structure of four alpha-helixes but only contains two of the four cysteines important in disulphide bond formation. It shows low amino acid identities (20-29%) with known IL-6 sequences, although phylogenetic analysis groups the Fugu molecule with the other IL-6 molecules. The gene organisation of Fugu IL-6 and the level of synteny between the human and Fugu genomes has been well conserved during evolution with the order and orientation of the genes matching exactly to human chromosome 7. PHA stimulation of Fugu kidney cells resulted in a large increase in the Fugu IL-6 transcript, whereas LPS and Poly I:C resulted in a significant increase within spleen cells. The discovery of IL-6 in fish will now allow more detailed investigations of local inflammatory responses.

Amino Acid Sequence↗
PubMed2002

cDNA sequence and tissue expression of Fugu rubripes prion protein-like: a candidate for the teleost orthologue of tetrapod PrPs.

We report the isolation and characterization of a cDNA coding for Fugu rubripes prion protein (PrP)-like of 180 amino acids which includes the PrP-conserved hydrophobic region homologous to that of Xenopus PrP. In addition to the hydrophobic region, Fugu PrP-like has several features common to PrPs, such as a signal sequence, a basic nature (pI 9.7) and a single intron in the 5' untranslated region. A possible glycosyl phosphatidylinositol (GPI) anchor site also exists in PrP-like. In expression analysis, PrP-like mRNA was detected in retina, skin, and brain, all of which express PrP mRNA in mammals. In a genome fragment clone (T002589, 31945 bp) sequenced by the Fugu Genomics Project, PrP-like located between KIAA0168 and SLC231A homologues. In human chromosome 20p13, PrP, Doppel, KIAA0168, and SLC231A align in this order. The close gene arrangement between the Fugu and human genomes suggests that Fugu PrP-like is a real orthologue of human PrP. However, Fugu PrP-like does not possess tandem repeats or a region with two glycosylation sites and a disulphide bridge. We do not declare that the cloned Fugu PrP-like represents fish PrP due to structural inconsistency, but believe that it will offer new insights into the evolution of PrPs from fish to tetrapods.

Amino Acid Sequence↗
PubMed2000

Characterization of the Fugu rubripes NLK and FN5 genes flanking the NF1 (Neurofibromatosis type 1) gene in the 5' direction and mapping of the human counterparts.

To complete the analysis of the Neurofibromatosis type 1 (NF1) gene region in Fugu rubripes, we characterized the upstream flanking region of the NF1 gene and identified the FN5 (flanking the Fugu NF1 gene in 5' direction) gene and the NLK (Nemo-like kinase) gene as its flanking genes. The FN5 gene spans 3807bp and encompasses four exons, three of which belong to the expanded 5' UTR. Only 11% of the FN5 transcript is protein-coding. The function of the FN5 protein spanning 59 amino acids is unknown. We also characterized the human and the mouse FN5 transcripts and found 85% and 83% similarity of deduced amino acid sequences compared with Fugu. Two copies of the human FN5 gene were identified, one on chromosome 17q21.3-q22 several megabases distal to the NF1 gene at 17q11.2. The second copy of the FN5 gene was mapped to 11q13.3-q23.3. In Fugu, the FN5 gene is flanked by the NLK gene, which spans 4513bp from the translation start to the stop codon and encompasses 11 exons. Comparing the deduced amino acid sequences, 82% overall similarity was observed between Fugu and mouse or human NLK and 67% similarity between the Fugu NLK and the highly related LIT-1 kinase of Caenorhabditis elegans, which has been shown, like the vertebrate counterpart, to be involved in the Wnt signalling pathway. We mapped the human NLK gene to 17q11.2 between markers D17S935 and D17S120, more than 1Mb proximal to the NF1 gene. The characterization of the 5' flanking region presented here, together with that of the 3' region, demonstrates the profound differences between Fugu and human considering the gene content within the region flanking the NF1 gene.

Amino Acid Sequence↗
PubMed2001

Intron loss in the SART1 genes of Fugu rubripes and Tetraodon nigroviridis.

The human SART1 gene was initially identified in a screen for proteins recognised by IgE, which may be implicated in atopic disease. We have examined the genomic structure and cDNA sequence of the SART1 gene in the compact genomes of the pufferfish Fugu rubripes and Tetraodon nigroviridis. The entire coding regions of both the Fugu and Tetraodon SART1 genes are contained within single exons. The Fugu gene contains only one intron located in the 5' untranslated region. Southern blot hybridisation of Fugu genomic DNA confirmed the SART1 gene to be single copy. Partial genomic structures were also determined for the human, mouse, Drosophila and C. elegans SART1 homologues. The human and mouse genes both contain many introns in the coding region, the human gene possessing at least 20 exons. The Drosophila and C. elegans homologues contain 6 and 12 exons, respectively. This is only the second time such a difference in the organization of homologous Fugu and human genes has been reported. The Fugu and Tetraodon SART1 genes encode putative proteins of 772 and 774 aa, respectively, each having 65% amino acid identity to human SART1. Leucine zipper and basic motifs are conserved in the predicted Fugu and Tetraodon proteins.

Amino Acid Sequence↗
PubMed2002

Fugu and human sequence comparison identifies novel human genes and conserved non-coding sequences.

The compact genome of the pufferfish, Fugu rubripes, has been proposed as a 'reference' genome to aid in annotating and analysing the human genome. We have annotated and compared 85 kb of Fugu sequence containing 17 genes with its homologous loci in the human draft genome and identified three 'novel' human genes that were missed or incompletely predicted by the previous gene prediction methods. Two of the novel genes contain zinc finger domains and are designated ZNF366 and ZNF367. They map to human chromosomes 5q13.2 and 9q22.32, respectively. The third novel gene, designated C9orf21, maps to chromosome 9q22.32. This gene is unique to vertebrates, and the protein encoded by it does not contain any known domains. We could not find human homologs for two Fugu genes, a novel chemokine gene and a kinase gene. These genes are either specific to teleosts or lost in the human lineage. The Fugu-human comparison identified several conserved non-coding sequences in the promoter and intronic regions. These sequences, conserved during 450 million years of vertebrate evolution, are likely to be involved in gene regulation. The 85 kb Fugu locus is dispersed over four human loci, occupying about 1.5 Mb. Contiguity is conserved in the human genome between six out of 16 Fugu gene pairs. These contiguous chromosomal segments should share a common evolutionary history dating back to the common ancestor of mammals and teleosts. We propose contiguity as strong evidence to identify orthologous genes in distant organisms. This study confirms the utility of the Fugu as a supplementary tool to uncover and confirm novel genes and putative gene regulatory regions in the human genome.

Amino Acid Sequence↗
PubMed1997

Genomic structure and sequence of the pufferfish (Fugu rubripes) growth hormone-encoding gene: a comparative analysis of teleost growth hormone genes.

A nested polymerase chain reaction (PCR) technique for amplifying a fragment of the gene (GH) encoding teleost growth hormone has been developed. Using this technique, a fragment of the pufferfish, Fugu rubripes and Arothron maculatus, dwarf gourami, Colisa lalia; guppy, Poecilia reticulata; and goldfish, Carassius auratus GH genes were cloned. The Fugu rubripes (Fugu) gene fragment was used to isolate the GH gene from a Fugu genomic library. The complete nucleotide sequence of a 8.5-kb SacI genomic fragment containing the Fugu GH gene has been determined. The GH gene spans 2.5 kb from the first codon to polyadenylation signal, and contains six exons and five introns similar to the GH genes of salmonids, tilapia, barramundi, flounder and yellowtail. The GH introns contain microsatellite and satellite sequences. The microsatellites found in the fifth intron of the GH gene are also present in the corresponding introns of tilapia, barramundi and flounder GH genes. Southern analysis revealed that the GH gene is a single-copy gene in the Fugu. The promoter region of the Fugu GH gene contains conserved sequences that are likely to be involved in the pituitary-specific expression of the gene. A phylogenetic tree of nucleotide (nt) sequences of all known teleost GH genes has been inferred using the distance matrix method. The topology of this tree reflects the major phylogenetic groupings of teleosts. The intron patterns and repetitive sequences of GH genes can serve as useful natural markers for the classification and phylogenetic studies of teleosts.

Amino Acid Sequence↗
PubMed1997

Cloning and sequencing of complement component C9 and its linkage to DOC-2 in the pufferfish Fugu rubripes.

The Japanese pufferfish Fugu rubripes has a 400 Mb genome with high gene density and minimal non-coding complexity, and is therefore an ideal vertebrate model for sequence comparison. The identification of regions of conserved synteny between Fugu and humans would greatly accelerate the mapping and ordering of genes. Fugu C9 was cloned and sequenced as a first step in an attempt to characterize the region in Fugu homologous to human chromosome 5p13. The 11 exons of the Fugu C9 gene share 33% identity with human C9 and span 2.9 kb of genomic DNA. By comparison, human C9 spans 90 kb, representing a 30-fold difference in size. We have also determined by cosmid sequence scanning that DOC-2, a tumour suppresser gene which also maps to human 5p13, lies 6-7 kb from C9 in a head-to-head or 5' to 5' orientation. These results demonstrate that the Fugu C9/DOC-2 locus is a region of conserved synteny. Sequence scanning of overlapping cosmids has identified two other genes, GAS-1 and FBP, both of which map to human chromosome 9q22, and lie adjacent to the Fugu C9/DOC-2 locus, indicating the boundary between two syntenic regions.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Extensive gene order differences within regions of conserved synteny between the Fugu and human genomes: implications for chromosomal evolution and the cloning of disease genes.

The suitability of the Fugu genome to facilitate the identification of candidate human disease genes using comparative positional cloning is dependent upon the extent to which synteny and gene order are conserved between the two species. We have cloned seven Fugu genes which are closely linked to Surfeit genes in two regions of the Fugu genome and have mapped and ordered their human homologues both by PCR analysis of the Genebridge 4 panel of radiation hybrids and by fluorescence in situ hybridization. All seven human genes map to a 3 Mb region of chromosome band 9q34.1, approximately 2-4 Mb proximal to the human Surfeit genes. Although both Fugu regions are syntenic with human chromosome band 9q34, the relative order of the genes differs greatly in the two species. Indeed, some of the genes that are adjacent in the Fugu genome are separated by at least 2-4 Mb in the human genome. This suggests that intra-chromosomal rearrangements, most probably inversions, have been common during the 900 million years of divergent evolution separating Fugu and human. The utility of Fugu to facilitate human disease gene identification by comparative positional cloning is questioned in light of these results.

Animals↗
PubMed2004

Erythropoietin gene from a teleost fish, Fugu rubripes.

In this paper we report the cloning and characterization of the erythropoietin (Epo) gene from the pufferfish, Fugu rubripes. This is the first nonmammalian Epo gene to be cloned. The Fugu Epo comprises 5 exons and 4 introns similar to the human EPO, and encodes a 185-amino acid protein that is 32% to 34% identical to Epo from various mammals. The synteny of genes at the Epo locus is conserved between the Fugu and humans. Unlike in mammals in which adult kidney is the primary Epo-producing organ, the heart is the main Epo-producing organ in adult Fugu. In addition to the heart, Fugu Epo is also expressed in the liver and brain similar to the human EPO. Interestingly, the transcripts in the Fugu brain are generated from a distal promoter and include an alternatively spliced first coding exon. No such brain-specific alternative splicing of Epo has been reported in mammals so far. Transient transfection studies in a fish hepatoma cell line (PLHC-1) and a human hepatoma cell line (HepG2) suggest that although the Fugu Epo promoter many not be hypoxia inducible, the gene may be regulated by hypoxia.

Animals↗
PubMed1995

Genomic structure and nucleotide sequence of the p55 gene of the puffer fish Fugu rubripes.

The p55 gene, which codes for a 55-kDa erythrocyte membrane protein, has been cloned and sequenced from the genome of the Japanese puffer fish Fugu rubripes (Fugu). This organism has the smallest recorded vertebrate genome and therefore provides an efficient way to sequence genes at the genomic level. The gene encoding p55 covers 5.5 kb from the beginning to the end of the coding sequence, four to six times smaller than the estimated size of the human gene, and is encoded by 12 exons. The structure of this gene has not been previously elucidated, but from this and other data we would predict a similar or identical structure in mammals. The predicted amino acid sequence of this gene in Fugu, coding for a polypeptide of 467 amino acids, is very similar to that of the human gene with the exception of the first two exons, which differ considerably. The predicted Fugu protein has a molecular weight (52.6 kDa compared with 52.3 kDa) and an isoelectric point very similar to those of human p55. In human, the p55 gene lies in the gene-dense Xq28 region, just 30 kb 3' to the Factor VIII gene, and is estimated to cover 20-30 kb. Its 5' end is associated with a CpG island, although there is no evidence that this is the case in Fugu. The small size of genes in Fugu and the high coding homology that they share with their mammalian equivalents, both in structure and sequence, make this compact vertebrate genome an ideal model for genomic studies.

Amino Acid Sequence↗
PubMed2000

Genomic structure and sequence of the leukocyte common antigen (CD45) from the pufferfish Fugu rubripes and comparison with its mammalian homologue.

The leukocyte common antigen (CD45) is a transmembrane protein tyrosine phosphatase expressed only in nucleated hematopoietic cells. It can be expressed as different isoforms depending on the cell type and the state of activation or differentiation and it is known to play a crucial role in the maturation and differentiation of B and T lymphocytes. However, the regulation of CD45 expression and function has been difficult to study due to the complexity of the gene in mammals. In this paper, we report the isolation and characterization of a CD45 orthologue gene from the Japanese pufferfish Fugu rubripes (Fugu). The Fugu CD45 cDNA sequence contains an open reading frame of 1,246 amino acids with a variable extracellular region as a result of the alternative splicing of two exons. The intracellular region is organized into two highly conserved tyrosine phosphatase domains. The extracellular region is not conserved except in some structural domains. The Fugu CD45 gene has a similar exon/intron organization to that of mammals except in the 5' end where some exons are missing or fused together. By contrast, the gene is ten times smaller in Fugu due to the small size of the introns. These studies show a greater flexibility to evolve at the 5' end of the gene and provide clues to the functionally important domains of the molecule. In addition, the lower complexity of this gene in Fugu should allow easier mapping of its regulatory sequences.

Amino Acid Sequence↗
PubMed2006

Fugu genome does not contain mitochondrial pseudogenes.

Contrary to previous observations that fish genomes are devoid of nuclear mitochondrial pseudogenes, a genome-wide survey identified a large number of "recent" and "ancient" nuclear mitochondrial DNA fragments (Numts) in the whole-genome sequences of the fugu (Takifugu rubripes), Tetraodon nigroviridis, and zebrafish (Danio rerio). We have analyzed the latest assembly (v4.0) of the fugu genome and show that, like the Anopheles genome, the fugu nuclear genome does not contain mitochondrial pseudogenes. Fugu assembly v4.0 contains a single scaffold representing the near complete sequence of the fugu mitochondria. The "recent" Numts identified by the previous study in fugu assembly v2.0 are in fact shotgun sequences of mitochondrial DNA that were misassembled with the nuclear sequences, whereas the "ancient" Numts appear to be the result of spurious matches. It is likely that the Numts identified in the genomes of Tetraodon and zebrafish are also similar artifacts. Shotgun sequences of whole genomes often include some mitochondrial sequences. Therefore, any Numts identified in shotgun-sequence assemblies should be verified by Southern hybridization or PCR amplification.

Animals↗
PubMed2003

Characterisation of a gene cluster in Fugu rubripes containing the complement component C4 gene.

In this study, we describe the characterisation of the complement component C4 gene in Fugu rubripes. The Fugu C4 gene, orthologous to the tetrapod C4 gene, encompasses a genomic span of 9702 base pairs and contains 41 exons, encoding the typical C4 three-chain polypeptide. The gene encodes a protein containing 1703 amino acids. The Fugu C4 protein demonstrates the presence of 25 conserved cysteine residues, as well as conservation of the functionally important thioester site. Complete sequencing of one cosmid and sequence scans from a cluster of 18 overlapping BAC clones, centering around the C4 gene, have identified the short-range linkage with five orthologous human genes mapping to the Major Histocompatibility Complex (MHC) including: tenascin X (TNX); cytochrome P450, subfamily XXIA, polypeptide 2 (CYP21A2); allograft inflammatory factor 1 (AIF1) and casein kinase 2, beta polypeptide (CSNK2B), all found in the MHC class III region; and retinoid X receptor, beta (RXRB),which resides in the MHC extended class II region. To date, this syntenic association of the Fugu C4 and other MHC class III region genes has not been observed in other teleost fish. Data from the recent whole-genome shotgun assemblies reveal the Fugu MHC-related cluster of genes to be flanked predominantly by genes mapping to human chromosomes 7 and 19. All of the six identified Fugu MHC-related genes have been characterised at the genomic level.

Amino Acid Sequence↗
PubMed1999

Characterization of three genes, AKAP84, BAW and WSB1, located 3' to the neurofibromatosis type 1 locus in Fugu rubripes.

Sequence analysis of cosmid clones was instrumental to identify three genes in the region flanking the Fugu rubripes NF1 gene in the 3' direction: the AKAP84 gene (A-kinase anchor protein 84), the WSB1 gene (WD-40-repeat protein with a SOCS box) and the BAW gene of yet unknown function located between the AKAP84 and the WSB1 genes. The human homologues of these genes are not located in the immediate vicinity of the NF1 gene at 17q11.2. Although synteny of the NF1, AKAP84, BAW and WSB1 genes is conserved between Fugu and human, the gene order is not conserved, and more than a simple inversion would have been necessary to explain the difference in gene order. The mammalian homologue of the Fugu BAW gene or protein has not yet been characterized. As deduced from the respective cDNAs, the Fugu AKAP84, WSB1 and BAW proteins vary concerning the overall degree of similarity to their mammalian counterparts. Whereas the overall similarity of AKAP84 between Fugu and mouse is low, three regions of known functional importance show considerable conservation. These are the N-terminal anchoring domain mediating the insertion of AKAP84 in the outer mitochondrial membrane, the binding site of the regulatory subunit (RI or RII) of protein kinase A, and the C-terminal domain present in the alternatively spliced isoform AKAP121 with an hnRNP K homology domain involved in RNA binding. A higher overall similarity of deduced protein sequences between Fugu and mouse was observed comparing the BAW gene products (74.1%) and the WSB1 proteins (77.2%).

A Kinase Anchor Proteins↗
PubMed2003

The nicotinic acetylcholine receptor gene family of the pufferfish, Fugu rubripes.

Nicotinic acetylcholine receptors (nAChRs) mediate fast cholinergic synaptic transmission at nerve-muscle junctions and in the brain. However, the complete gene family of nAChRs has not so far been reported for any vertebrate organism. We have identified the complete nAChR gene family from the reference genome of the pufferfish, Fugu rubripes. It consists of 16 alpha and 12 non-alpha candidate subunits, making it the largest vertebrate nAChR gene family known to date. The gene family includes an unusual set of muscle-like nAChR subunits comprising two alpha1s, two beta1s, one delta, one epsilon, and one gamma. One of the beta1 subunits possesses an aspartate residue and N-glycosylation sites hitherto shown to be necessary for delta-subunit function. Potential Fugu orthologs of neuronal nAChR subunits alpha2-4, alpha6, and beta2-4 have been identified. Interestingly, the Fugu alpha5 counterpart appears to be a non-alpha subunit. Fugu possesses an expanded set of alpha7-9-like subunits and no alpha10 ortholog has been found. Two new candidate beta subtypes, designated beta5 and beta6, may represent subunits yet to be found in the human genome. The Fugu nAChR gene structures are considerably more diverse than those of higher vertebrates, with evidence of "intron gain" in many cases. We show, using RT-PCR, that the Fugu nAChR subunits are expressed in a variety of tissues.

Amino Acid Sequence↗