{PDOC00412}
{PS00447; DNA_POLYMERASE_A}
{BEGIN}
*************************************
* DNA polymerase family A signature *
*************************************

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 gamma (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.

-Consensus pattern: R-x(2)-[GSAV]-K-x(3)-[LIVMFY]-[AGQ]-x(2)-Y-x(2)-[GS]-x(3)-
                    [LIVMA]
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in Swiss-Prot: 2.
-Last update: November 1995 / Pattern and text revised.

[ 1] Delarue M., Poch O., Tordo N., Moras D., Argos P.
     "An attempt to unify the structure of polymerases."
     Protein Eng. 3:461-467(1990).
     PubMed=2196557
[ 2] Ito J., Braithwaite D.K.
     "Compilation and alignment of DNA polymerase sequences."
     Nucleic Acids Res. 19:4045-4057(1991).
     PubMed=1870963
[ 3] Braithwaite D.K., Ito J.
     "Compilation, alignment, and phylogenetic relationships of DNA
     polymerases."
     Nucleic Acids Res. 21:787-802(1993).
     PubMed=8451181

--------------------------------------------------------------------------------
PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and
distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives
(CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html
--------------------------------------------------------------------------------

{END}