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B D Hall

Publications and source records attributed to B D Hall.

At least 91 records · Page 5Linked to original sources
PubMed1987

Expression of the Escherichia coli xylose isomerase gene in Saccharomyces cerevisiae.

Transformation of Saccharomyces cerevisiae by yeast expression plasmids bearing the Escherichia coli xylose isomerase gene leads to production of the protein. Western blotting (immunoblotting) experiments show that immunoreactive protein chains which comigrate with the E. coli enzyme are made in the transformant strains and that the amount produced parallels the copy number of the plasmid. When comparable amounts of immunologically cross-reactive xylose isomerase protein made in E. coli or S. cerevisiae were assayed for enzymatic activity, however, the yeast protein was at least 10(3)-fold less active.

Aldose-Ketose Isomerases↗
PubMed1987

Thumb polydactyly as a part of the range of genetic expression for thenar hypoplasia.

Attempts to study the genetics of human thumb polydactyly have been hampered by lack of awareness of the extremely varied expression of upper limb preaxial anomalies. It has been appreciated that thumb polydactyly could range from a broadened distal phalanx to complete duplication of the entire thumb. Most cases are sporadic and unilateral, but rare familial cases with wide variability and occasional nonpenetrance have been described. Four unrelated families are described who have thumb polydactyly as part of the range of expression for a dominant gene that is frequently associated with absence of thenar intrinsic muscles and flexor pollicis longus with inability to flex the thumb across the palm (the Fromont anomaly). These families and previous literature reports suggest that expression of the gene can range from thumb hypoplasia (most commonly the Fromont anomaly) to triphalangeal thumb or thumb polydactyly. As a consequence of this experience, we urge that parents, siblings, and other close relatives of patients born with thumb polydactyly be carefully examined for mild degrees of thumb hypoplasia or any other thumb anomaly, and that these findings be considered when providing recurrence risk counseling.

Adolescent↗
PubMed1986

Effects of tRNATyr point mutations on the binding of yeast RNA polymerase III transcription factor C.

A physical DNA binding assay was employed to analyze the binding of yeast RNA polymerase III transcription factor C (TFIIIC) to tRNA genes. The assay allowed us to measure the equilibrium constants for specific and nonspecific TFIIIC-DNA binding and to assess the effects of tRNATyr-DNA gene promoter mutations on binding. Sequence alterations in the B block element of the promoter greatly affect the equilibrium constant for specific TFIIIC binding (K8). Mutations which decrease tRNATyr homology to the recognized B block consensus sequence drastically reduce K8 (43- to 370-fold), while mutations which increase homology increase K8 (4- to 5-fold). By contrast, point mutations in the A block element of the tRNATyr promoter have less than 2-fold effects on K8; however, total deletion of A block sequences reduces K8 2- to 5-fold. These results indicate that TFIIIC-rTNA gene binding involves interactions with both A block and B block sequences, but B block interactions dominate, and the relative contribution of A block interactions is small. Since A block sequences are absolutely required for active tRNA gene transcription, the binding results suggest that the role of A block sequences in transcription is not confined solely to TFIIIC binding.

Base Sequence↗
PubMed1985

Effects of alterations in the 3' flanking sequence on in vivo and in vitro expression of the yeast SUP4-o tRNATyr gene.

The SUP4-o gene of Saccharomyces cerevisiae codes for an altered tRNATyr capable of suppressing ochre mutations. We constructed mutant SUP4-o genes with deletions in the 3'-flanking sequence and tested each for its ability to suppress ochre mutations in transformed yeast cells. The effects of the different 3' deletions on various aspects of in vitro transcription and RNA processing were also determined, using a yeast cell-free extract. Deletions that leave five or fewer consecutive T residues in the 3'-flanking sequence of SUP4-o were found to result in decreased efficiency of transcription termination, both in vitro and in vivo. Unexpectedly, the suppression strength of each mutant SUP4-o gene is highly correlated with the relative extent of transcription termination at the 3' end of the gene. This result indicates that SUP4-o readthrough transcripts are not efficiently processed to functional suppressor tRNA in yeast cells. Deletions that extend into the T cluster in the 3'-flanking sequence also significantly decrease the ability of SUP4-o to compete for a transcription factor that is limiting in our extracts. This latter finding implies that the 3'-flanking sequence of SUP4 plays a role in transcription factor binding.

Chromosome Deletion↗
PubMed1985

Nucleotide sequence of the GDH gene coding for the NADP-specific glutamate dehydrogenase of Saccharomyces cerevisiae.

The isolation of the Saccharomyces cerevisiae gene for NADP-dependent glutamate dehydrogenase (NADP-GDH) by cross hybridization to the Neurospora crassa am gene, known to encode for NADP-GDH is described. Two DNA fragments selected from a yeast genomic library in phage lambda gt11 were shown by restriction analysis to share 2.5 kb of common sequence. A yeast shuttle vector (CV13) carrying either to the cloned fragments complements the gdh- strain of S. cerevisiae and directs substantial overproduction of NADP-GDH. One of the cloned fragments was sequenced, and the deduced amino acid (aa) sequence of the yeast NADP-GDH is 64% homologous to N. crassa, 51% to Escherichia coli and 24% to bovine NADP-GDHs.

Amino Acid Sequence↗
PubMed1985

Tarsal and carpal coalition and symphalangism of the Fuhrmann type. Report of a family.

We are reporting on fifteen members of a five-generation family (sixty-three members) who had an autosomal dominant osseous disorder that was characterized by tarsal and carpal coalition, symphalangism, short first metacarpals, and abnormalities of the elbow, including humeroradial fusion. This family is similar to the one reported by Fuhrmann et al.

Adolescent↗
PubMed1984

Structural features of yeast tRNA genes which affect transcription factor binding.

Transcription of yeast tRNA genes in vitro requires, in addition to RNA polymerase III, two accessory factors which are resolved by ion-exchange chromatography. One of these transcription factors (factor C) binds to tRNA genes. The stability of factor C-tRNA gene complexes is gene-dependent: the tRNAAGGArg gene forms a highly stable complex while tRNA3Leu and tRNATyr gene complexes are unstable under our standard assay conditions. To determine how differences in tRNA gene structure affect factor C binding, mutant tRNATyr genes, internally deleted tRNA3Leu genes and hybrid transcription units containing both tRNATyr and tRNA3Leu segments were compared in their abilities to stably bind factor C. Sequence changes in either of the two highly conserved promoter elements (A block and B block) affect factor C complex stability. Changes towards the consensus sequence increase complex stability while changes away from the consensus sequence drastically reduce stability. Also, the distance separating the A and B blocks affects complex stability; 34-53 bp gives highest stability. These results indicate that the stable binding of transcription factor C to tRNA genes involves interactions with both A block and B block sequences.

Base Sequence↗
PubMed1984

Xylose isomerase from Escherichia coli. Characterization of the protein and the structural gene.

The gene that codes for xylose isomerase in Escherichia coli has been cloned by complementation of a xylose isomerase-negative E. coli mutant. The structural gene is 1320 nucleotides in length and codes for a protein of 440 amino acids. An additional 209 nucleotides 5' and 82 nucleotides 3' to the structural gene were also sequenced. To verify that the cloned gene encodes E. coli xylose isomerase, the enzyme was purified to homogeneity and the sequence of the first 25 amino acid residues was determined by a semimicromanual Edman procedure. These results establish that the NH2-terminal methionine of xylose isomerase is specified by an ATG which is 7 nucleotides downstream from a Shine-Dalgarno sequence.

Aldose-Ketose Isomerases↗
PubMed1984

Parietal foramina clavicular hypoplasia. An autosomal dominant syndrome.

A male infant was evaluated with macrocephaly, scaphocephaly , a high forehead, a parietal foramen, a midline posterior occipital dermoid, and sloped shoulders. A skeletal survey also showed distal hypoplasia of the clavicles with bilateral loss of the acromion. Similar features were evident in his father, grandfather, and two paternal great-aunts. To our knowledge, this is the second report of this syndrome, which may be designated as parietal foramina-cleidocranial dysplasia. Our three-generation family and male-to-male transmission clearly established an autosomal dominant mode of inheritance for this syndrome.

Adult↗