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* mutT domain signature *
*************************

The bacterial  mutT  protein  is involved in the GO system [1] responsible for
removing an   oxidatively   damaged   form  of  guanine  (8-hydroxyguanine  or
7,8-dihydro-8-oxoguanine) from  DNA  and  the  nucleotide  pool. 8-oxo-dGTP is
inserted opposite  to  dA  and  dC  residues of template DNA with almost equal
efficiency thus  leading  to  A.T  to  G.C  transversions.  MutT  specifically
degrades 8-oxo-dGTP  to  the  monophosphate  with  the  concomitant release of
pyrophosphate. MutT is a small protein of about 12 to 15 Kd.

It has  been shown [2] that a region of about 40 amino acid residues, which is
found in  the N-terminal part of mutT, can also be found in a variety of other
prokaryotic, viral, and eukaryotic proteins. These proteins are:

 - A mutT homolog from plasmid pSAM2 of Streptomyces ambofaciens.
 - Bartonella bacilliformis invasion protein A (gene invA).
 - Escherichia coli hypothetical protein yebD.
 - Escherichia coli hypothetical protein yjaD.
 - Protein D250 from African swine fever viruses.
 - Proteins D9 and D10 from a variety of poxviruses.
 - Human 7,8-dihydro-8-oxoguanine triphosphatase [3].
 - A  protein  encoded  on  the  antisense  RNA of the basic fibroblast growth
   factor gene in higher vertebrates.

It is  proposed  [2] that the conserved domain could be involved in the active
center of a family of pyrophosphate-releasing NTPases.  As a signature pattern
we selected the  core  region  of  the  domain;  it  contains  four  conserved
glutamate residues.

-Consensus pattern: G-x(5)-E-x(4)-[STAGC]-[LIVMA]-x-R-E-[LIVMF]-x-E-E
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in SWISS-PROT: NONE.

-Expert(s) to contact by email: Koonin E.V.
                                koonin@ncbi.nlm.nih.gov

-Last update: June 1994 / Text revised.

[ 1] Michaels M.L., Miller J.H.
     J. Bacteriol. 174:6321-6325(1992).
[ 2] Koonin E.V.
     Nucleic Acids Res. 21:4847-4847(1993).
[ 3] Sakumi K., Furuichi M., Tsuzuki T., Kakuma T., Kawabata S., Maki H.,
     Sekiguchi M.
     J. Biol. Chem. 268:23524-23530(1993).