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- ****************************************
- * AP endonucleases family 2 signatures *
- ****************************************
-
- DNA damaging agents such as the antitumor drugs bleomycin and neocarzinostatin
- or those that generate oxygen radicals produce a variety of lesions in DNA.
- Amongst these is base-loss which forms apurinic/apyrimidinic (AP) sites or
- strand breaks with atypical 3'termini. DNA repair at the AP sites is initiated
- by specific endonuclease cleavage of the phosphodiester backbone. Such
- endonucleases are also generally capable of removing blocking groups from the
- 3'terminus of DNA strand breaks.
-
- AP endonucleases can be classified into two families on the basis of sequence
- similarity. What we call family 2 groups the enzymes listed below [1].
-
- - Escherichia coli endonuclease IV (EC 3.1.21.2) (gene nfo).
- - Mycobacterium leprae probable endonuclease (gene end) [2].
- - Yeast apurinic endonuclase APN1.
-
- APN1 and nfo have been shown [3] to be transition metalloproteins that seem to
- bind zinc and manganese.
-
- We developed three signature patterns for this family of enzymes. The patterns
- are based on regions that contain conserved cysteines and histidines which
- could be involved in binding metal ions.
-
- -Consensus pattern: H-x(2)-Y-[LIVMF]-I-N-[LIVM]-[AG]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: G-[LIVMF]-C-[LIVM]-D-T-C-H
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: [LIVM]-H-x-N-D-[SA]-K-x(3)-G-[SA]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: June 1994 / Patterns and text revised.
-
- [ 1] Popoff S.C., Spira A.I., Johnson A.W., Demple B.
- Proc. Natl. Acad. Sci. U.S.A. 87:4193-4197(1990).
- [ 2] Honore N.T., Bergh S., Chanteau S., Doucet-Populaire F., Eiglmeier K.,
- Garnier T., Georges C., Launois P., Limpaiboon T., Newton S., Niang K.,
- del Portillo P., Ramesh G.R., Reddi P., Ridel P.R., Sittisombut N.,
- Wu-Hunter S., Cole S.T.
- Mol. Microbiol. 7:207-214(1993).
- [ 3] Levin J.D., Shapiro R., Demple B.
- J. Biol. Chem. 266:22893-22898(1991).
-