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We are deeply saddened by the passing of Amos Bairoch (1957–2025), the creator of PROSITE. We wish to dedicate our latest paper, published shortly before his death, to him. He will always be a source of inspiration to us.
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Amos Bairoch

PROSITE documentation PDOC00412
DNA polymerase family A signature


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PURL: https://purl.expasy.org/prosite/documentation/PDOC00412

Description

Replicative DNA polymerases (EC 2.7.7.7) are the key enzymes catalyzing the accurate replication of DNA. They require either a small RNA molecule or a protein as a primer for the de novo synthesis of a DNA chain. On the basis of sequence similarities a number of DNA polymerases have been grouped together [1,2,3] under the designation of DNA polymerase family A. The polymerases that belong to this family are listed below.

  • Escherichia coli and various other bacterial polymerase I (gene polA).
  • Thermus aquaticus Taq polymerase.
  • Bacteriophage sp01 polymerase.
  • Bacteriophage sp02 polymerase.
  • Bacteriophage T5 polymerase.
  • Bacteriophage T7 polymerase.
  • Mycobacteriophage L5 polymerase.
  • Yeast mitochondrial polymerase γ (gene MIP1).

Five regions of similarity are found in all the above polymerases. One of these conserved regions, known as 'motif B' [1], is located in a domain which, in Escherichia coli polA, has been shown to bind deoxynucleotide triphosphate substrates; it contains a conserved tyrosine which has been shown, by photo-affinity labelling, to be in the active site; a conserved lysine, also part of this motif, can be chemically labelled, using pyridoxal phosphate. We use this conserved region as a signature for this family of DNA polymerases.

Last update:

November 1995 / Pattern and text revised.

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Technical section

PROSITE method (with tools and information) covered by this documentation:

DNA_POLYMERASE_A, PS00447; DNA polymerase family A signature  (PATTERN)


References

1AuthorsDelarue M. Poch O. Tordo N. Moras D. Argos P.
TitleAn attempt to unify the structure of polymerases.
SourceProtein Eng. 3:461-467(1990).
PubMed ID2196557

2AuthorsIto J. Braithwaite D.K.
TitleCompilation and alignment of DNA polymerase sequences.
SourceNucleic Acids Res. 19:4045-4057(1991).
PubMed ID1870963

3AuthorsBraithwaite D.K. Ito J.
TitleCompilation, alignment, and phylogenetic relationships of DNA polymerases.
SourceNucleic Acids Res. 21:787-802(1993).
PubMed ID8451181



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