Gene: [08p1/POLB] polymerase (DNA directed), beta;


FUN

[1] Low-molecular (42558 kD, 381 amino acids) N-ethyl maleimide-resistant DNA polymerase beta probably participates in the reparation of DNA breaks and hence may be involved into pathogenesis of xeroderma pigmentosum, ataxia-telangiectasia, and Fanconi's anemia.
[2] The reaction catalyzed: N-deoxynucleoside triphosphate = N-pyrophosphate + DNA(N)."

EVO

Of 4750 amino acid sequences (data bank PIR), POLB exhibits a significant homology only with terminal deoxynucleotidyl exotransferase (GEM:10q2/DNTT): there are 24% identical amino acid residues and 21% conservative amino acid changes. A duplication of an ancestral gene with consequent divergence of POLB and DNTT about 250 Myr ago (before the wide spreading of birds an mammals) is supposed."

FAG

The gene coding for alpha form of DNA-dependent DNA polymerase is mapped to X chromosome: GEM:0Xp2/POLA."

PRO

Probes pB19 (740 bp) and pB159 (1215 bp) contain cDNA fragments cloned in the plasmid pUC-8; the stop codon TGA occupies the position 1142-43-44 bp in the cDNA (the total size is 1319 bp)."

POL

Probe pUC9-10F (438 bp of 5'-terminal EcoRI fragment of rat cDNA) reveals several RFLPs (EcoRI, HindIII, BamHI, SacI, PvuII) within the 5'-vicinity of human POLB."

REF

MOP,SEQ,EVO "Anderson &: Gene, 60, 163-173, 1987
LOC,MOL,CYG "Cannizzaro &: CCG, 47, 121-124, 1988
LOC,MOL,CYG "Matsukage A &: Jpn J Cancer Res, 77, 330-333, 1986
LOC,MOL,CYG "McBride OW &: PNAS, 84, N2, 503-507, 1987
CLO,SEQ,EXP "SenGupta DN &: BBRC, 136, 341-347, 1986
REV,MOL,EXP "Wilson S &: BBA, 949, 149-157, 1988

SWI

 SWISSPROT: P06746

KEY

repr, nucm

CLA

coding, basic

LOC

08 p12-11

MIM

 MIM: 174760

EZN

 ENZYME: 2.7.7.7