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L T Hunt

Publications and source records attributed to L T Hunt.

At least 55 records · Page 3Linked to original sources
PubMed1987

A domain structure common to hemopexin, vitronectin, interstitial collagenase, and a collagenase homolog.

The sequence of hemopexin consists almost entirely of two homologous domains joined by a short hinge region; the domain structure, with its own characteristic features, is derived from four short tandem repeats. Each repeat contains several alternating clusters of hydrophobic and hydrophilic residues but also has some individual features as a consequence of its position in the domain. Here we present evidence for the presence of a single hemopexin domain in an interstitial collagenase and in a collagenase homolog, as well as of two copies of the domain in vitronectin. The functions of all of these proteins involve binding to various proteins and smaller molecules. We suggest that the presence of this domain may facilitate these binding activities. Our analysis also suggests a tentative identification of substrate-binding and catalytic domains in the collagenase and its homolog.

Amino Acid Sequence↗
PubMed1986

The protein identification resource (PIR).

The Protein Identification Resource, which provides the scientific community with an efficient on-line computer system designed for the identification and analysis of protein sequences and their corresponding coding sequences, has been established. The resource consists of an integrated computer system composed of a number of protein and nucleic acid sequence databases and the software necessary to analyze this information effectively.

Amino Acid Sequence↗
PubMed1985

New perspectives on bacterial ferredoxin evolution.

Recent evidence indicates that a gene transposition event occurred during the evolution of the bacterial ferredoxins subsequent to the ancestral intrasequence gene duplication. In light of this new information, the relationships among the bacterial ferredoxins were reexamined and an evolutionary tree consistent with this new understanding was derived. The bacterial ferredoxins can be divided into several groups based on their sequence properties; these include the clostridial-type ferredoxins, the Azotobacter-type ferredoxins, and a group containing the ferredoxins from the anaerobic, green, and purple sulfur bacteria. Based on sequence comparison, it was concluded that the amino-terminal domain of the Azotobacter-type ferredoxins, which contains the novel 3Fe:3S cluster binding site, is homologous with the carboxyl-terminal domain of the ferredoxins from the anaerobic photosynthetic bacteria. A number of ferredoxin sequences do not fit into any of the groups described above. Based on sequence properties, these sequences can be separated into three groups: a group containing Methanosarcina barkeri ferredoxin and Desulfovibrio desulfuricans ferredoxin II, a group containing Desulfovibrio gigas ferredoxin and Clostridium thermoaceticum ferredoxin, and a group containing Desulfovibrio africanus ferredoxin I and Bacillus stearothermophilus ferredoxin. The last two groups differ from all of the other bacterial ferredoxins in that they bind only one Fe:S cluster per polypeptide, whereas the others bind two. Sequence examination indicates that the second binding site has been either partially or completely lost from these ferredoxins. Methanosarcina barkeri ferredoxin and Desulfovibrio desulfuricans ferredoxin II are of interest because, of all the ferredoxins whose sequences are presently known, they show the strongest evidence of internal gene duplication.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1985

The prokaryote-eukaryote interface.

Over the past 30 years the study of the sequences of proteins and nucleic acids has produced almost incredible amounts of information, new concepts, and new avenues of research. The beginning was slow: the first peptide hormones sequenced in the early 1950's, the first cytochrome c (horse) in 1961, the first bacterial ferredoxin in 1964, and the first transfer RNA (yeast alanine tRNA) in 1965. In the past 6 years, the rate of data accumulation has accelerated tremendously, primarily due to technological advances in nucleic acid sequencing techniques. For investigators of biological evolution, the sequence data and the new information on genetic mechanisms would prove to be the best evidence for elucidating relationships among the genomes of living organisms and for deducing phylogenetic history. In particular, they needed evidence to decide between the two hypotheses for the origin of eukaryotic cells. Now, less than 20 years since Margulis renewed the investigation of this problem, comparisons of protein and nucleic acid sequences, especially of the small subunit ribosomal RNAs, have answered this question in favor of the endosymbiotic origin of eukaryotic cells. After briefly discussing some of the concepts that helped resolve this controversy and the problems involved in using sequence data for evolutionary studies, we describe a few examples of useful evolutionary trees.

Amino Acid Sequence↗
PubMed1984

Identification of the probable coding region for exon 2 of cytochrome oxidase polypeptide I from Aspergillus nidulans mitochondrion.

Hypothetical protein URFe of Aspergillus nidulans mitochondrion is homologous with the amino end of cytochrome oxidase (EC 1.9.3.1) polypeptide I. Unidentified reading frame URFe does not contain a suitable initiation codon and codes for a protein with a length of only 91 residues, corresponding to about 20% of cytochrome oxidase polypeptide I. It is proposed that this region codes for the second exon of the cox 1 gene of Aspergillus mitochondrion. Possible candidates for the 2- to 3-residue amino-terminal exon 1 are discussed.

Amino Acid Sequence↗
PubMed1984

Vaccinia virus 19-kilodalton protein: relationship to several mammalian proteins, including two growth factors.

We observed two unusual patterns of cysteine and glycine residues in transforming growth factor type 1 (TGF1); our computer search found only one other protein, the 19-kilodalton early protein of vaccinia virus, having both patterns. The sequences of epidermal growth factor (EGF) and of the light chains from several components of the blood coagulation system also have one of the patterns, but gaps are required to adjust conserved cysteine and glycine residues in the second pattern. We used several computer analyses to confirm these relationships; the 19-kilodalton protein appears to be related to TGF1 and EGF to the same degree that they are related to each other; all three are more distantly related to the coagulation factors. An evolutionary scheme is presented for these proteins. We suggest that the conservation of cysteine residues, which form the disulfide bonds present in the active EGF molecule, may extend to conservation of disulfide bonds in these other proteins. We also suggest that the structural similarities may be correlated with a protein-binding capability.

Amino Acid Sequence↗
PubMed1981

Data bank.

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Base Sequence↗