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W C Barker

Publications and source records attributed to W C Barker.

87 records · Page 5Linked to original sources
PubMed1982

Viral src gene products are related to the catalytic chain of mammalian cAMP-dependent protein kinase.

The transforming protein sequences translated from the Rous avian and Moloney murine sarcoma virus src genes are shown to be related to the catalytic chain of bovine cAMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37). The avian transforming protein, also a protein kinase, shows greatest homology with the bovine protein kinase in the carboxyl-terminal half, where the protein kinase activity is localized. Moreover, lysine occurs in the inferred transforming protein sequences at the position homologous with the proposed ATP-binding lysine of the bovine protein kinase. This relationship is consistent with the hypothesis that the src genes originated in the host genomes, in which they are members of a superfamily of distantly related protein kinases that are normal constituents of mammalian cells. In the host, these sequences are much more highly conserved than in the viruses.

Amino Acid Sequence↗
PubMed1981

Data bank.

Explore the source record for details and available documents.

Base Sequence↗
PubMed1980

Nucleic acid sequence bank.

In the report by T. Kakunaga and J. D. Crow (25 July, p. 505), Fig. 1 on page 506 should have been printed as follows: [See figure in the PDF file]

Base Sequence↗
PubMed1980

Origins of immunoglobulin heavy chain domains.

Using computer programs that analyze the evolutionary history and probability of relationship of protein sequences, we have investigated the gene duplication events that led to the present configuration of immunoglobulin C regions, with particular attention to the origins of the homology regions (domains) of the heavy chains. We conclude that all of the sequenced heavy chains share a common ancestor consisting of four domains and that the two shorter heavy chains, alpha and gamma, have independently lost most of the second domain. These conclusions allow us to align corresponding regions of these sequences for the purpose of deriving evolutionary trees. Three independent internal gene duplications are postulated to explain the observed pattern of relationships among the four domains: first a duplication of the ancestral single domain C region, followed by independent duplications of the resulting first and last domains. In these studies there was no evidence of crossing-over and recombination between ancestral chains of different classes; however, certain types of recombinations would not be detectable from the available sequence data.

Biological Evolution↗
PubMed1979

Evolution of homologous physiological mechanisms based on protein sequence data.

1. Genetic duplications can give rise to homologous physiological mechanisms that include structurally related protein components. There are many such examples of related proteins within the human body. 2. Evolutionary histories showing the origins and subsequent divergences of these distantly related proteins can be derived from the protein sequences and correlated with the functional characteristics of these proteins. 3. The hormones related to glucagon provide an example of homology of physiological mechanisms and emergence of new functions subsequent to gene duplications. 4. The proteins related to troponin C illustrate the participation of distantly related proteins in the same mechanism (muscle contraction), the relationship of proteins characteristic of a specialized tissue to proteins found in all eukaryote cells, and the correlation of genetic duplications with the evolutionary appearance of different types of muscle.

Amino Acid Sequence↗
PubMed1978

A comprehensive examination of protein sequences for evidence of internal gene duplication.

We have implemented a routine procedure for screening protein sequences for evidence of intragenic duplications. We tested 163 protein sequences representing 116 superfamilies of unrelated proteins. Twenty superfamilies contain proteins with internal gene duplications. The intragenic duplications detected can be divided into two major types. (1) One or more duplications of all or part of a gene produce a protein with two or several detectable regions of sequence homology. Sequences from 18 superfamilies contained this type of duplication. (2) Repeated reduplication of a small DNA segment can produce a protein that is repetitive over most of its length. Three superfamilies contain such repetitive sequences. We also investigated the limits of detection of ancient duplications using sequences derived by random mutation of a model sequence consisting of ten 10-residue repeats. The original repetitive nature of the sequence was usually detected after 250 point mutations even though the ancestral segment could not be accurately reconstructed.

Amino Acid Sequence↗
PubMed1977

Evolution of lipoproteins deduced from protein sequence data.

1. Human serum apolipoprotein A-I contains a prominent 11-residue sequence periodicity. 2. Similar 11-residue segments occur in the other sequenced human apolipoproteins, C-I, C-III, and A-II. 3. Computer analyses of the sequences support the hypothesis that they evolved from a common ancestor. 4. An evolutionary history of these proteins is proposed. 5. The estimated rate of change of these proteins indicates that all four types will be found throughout the vertebrates and that related proteins will also be found in invertebrates.

Amino Acid Sequence↗