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T5 DNA polymerase: structural--functional relationships to other DNA polymerases.

ABSTRACT: T5 DNA polymerase, a highly processive single-polypeptide enzyme, has been analyzed for its primary structural features. The amino acid sequence of T5 DNA polymerase has a high degree of homology with that of DNA polymerase I from Escherichia coli and retains many of the amino acid residues that have been implicated in the 3'----5' exonuclease and DNA polymerase activities of that enzyme. Alignment with sequences of polymerase I and T7 DNA polymerase was used to identify regions possibly involved in the high processivity of this enzyme. Further, amino acid sequence comparisons of T5 DNA polymerase with a large group of DNA polymerases previously shown to exhibit little similarity to polymerase I indicate certain sequence segments are shared among distantly related DNA polymerases. These shared regions have been implicated in the 3'----5' exonuclease function of polymerase I, which suggests that the proofreading domains of all these enzymes may be evolutionarily related.

SUBMITTER: Leavitt MC

PROVIDER: S-EPMC287290 | biostudies-other | 1989 Jun

REPOSITORIES: biostudies-other

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T5 DNA polymerase: structural--functional relationships to other DNA polymerases.

Leavitt M C MC Ito J J

Proceedings of the National Academy of Sciences of the United States of America 19890601 12

T5 DNA polymerase, a highly processive single-polypeptide enzyme, has been analyzed for its primary structural features. The amino acid sequence of T5 DNA polymerase has a high degree of homology with that of DNA polymerase I from Escherichia coli and retains many of the amino acid residues that have been implicated in the 3'----5' exonuclease and DNA polymerase activities of that enzyme. Alignment with sequences of polymerase I and T7 DNA polymerase was used to identify regions possibly involve ...[more]

PMID: 2660138

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