>TIGR00600 rad2 DNA excision repair protein (rad2); InterPro: IPR001044 Xeroderma pigmentosum (XP) is a human autosomal recessive disease, characterised by a high incidence of sunlight-induced skin cancer. People's skin cells with this condition are hypersensitive to ultraviolet light, due to defects in the incision step of DNA excision repair. There are a minimum of seven genetic complementation groups involved in this pathway: XP-A to XP-G. XP-G is one of the most rare and phenotypically heterogeneous of XP, showing anything from slight to extreme dysfunction in DNA excision repair , . XP-G can be corrected by a 133 Kd nuclear protein, XPGC . XPGC is an acidic protein that confers normal UV resistance in expressing cells . It is a magnesium-dependent, single-strand DNA endonuclease that makes structure-specific endonucleolytic incisions in a DNA substrate containing a duplex region and single-stranded arms , . XPGC cleaves one strand of the duplex at the border with the single-stranded region . XPG belongs to a family of proteins that includes RAD2 from Saccharomyces cerevisiae (Baker's yeast) and rad13 from Schizosaccharomyces pombe (Fission yeast), which are single-stranded DNA endonucleases , ; mouse and human FEN-1, a structure-specific endonuclease; RAD2 from fission yeast and RAD27 from budding yeast; fission yeast exo1, a 5'-3' double-stranded DNA exonuclease that may act in a pathway that corrects mismatched base pairs; yeast DHS1, and yeast DIN7. Sequence alignment of this family of proteins reveals that similarities are largely confined to two regions. The first is located at the N-terminal extremity (N-region) and corresponds to the first 95 to 105 amino acids. The second region is internal (I-region) and found towards the C-terminus; it spans about 140 residues and contains a highly conserved core of 27 amino acids that includes a conserved pentapeptide (E-A-[DE]-A-[QS]). It is possible that the conserved acidic residues are involved in the catalytic mechanism of DNA excision repair in XPG. The amino acids linking the N- and I-regions are not conserved. This entry represents XPGC, an acidic protein that confers normal UV resistance in expressing cells, can correct XP-G. It is a magnesium-dependent, single-strand DNA endonuclease that makes structure-specific endonucleolytic incisions in a DNA substrate containing a duplex region and single-stranded arms. XPGC cleaves one strand of the duplex at the border with the single-stranded region , .; GO: 0003697 single-stranded DNA binding, 0004519 endonuclease activity, 0006289 nucleotide-excision repair, 0005634 nucleus.

Probab=98.87  E-value=4.6e-08  Score=77.41  Aligned_cols=73  Identities=22%  Similarity=0.258  Sum_probs=50.9

Q ss_pred             CCEEEEEECCHHHHHHHHCCCCCCCCCCCCEECHHHHHHHHHHHHHH-HHCCCCCCCEEEEEEECCCCCHHHHCCHHHHC
Q ss_conf             97289996626999887426754468988550069999999999999-84855479879999727488713240865216
Q gi|254780277|r    4 ENHLFLVDGSSFIYRAFYATPLLSRKHDGLPVNAIAGFCNMLWKLLQ-NSRKESIASHFAVIFDYPAVTFRNEIYPDYKA   82 (976)
Q Consensus         4 ~~~~~liDg~~~~~ra~~a~p~~~~~~~G~~t~ai~gf~~~l~~~i~-~~~~~~~~~~~~v~fD~~~~tfR~~~~~~YKa   82 (976)
T Consensus        23 e~K~LAvD~SIWlyQ~LKaVRD~~GN--~i~n~Hl~tlF~RlCKLLFFrIrP-------vFVFDG~aP~LKrqTl~kR~~   93 (1127)
T TIGR00600        23 EGKRLAVDISIWLYQALKAVRDREGN--AIKNSHLLTLFRRLCKLLFFRIRP-------VFVFDGGAPLLKRQTLAKRRQ   93 (1127)
T ss_pred             CCCEEEHHHHHHHHHHHHHHCCCCCC--EEECCHHHHHHHHHHHHHHCCCCE-------EEEECCCCCCHHHHHHHHHHH
T ss_conf             14340124648999876222003687--230506677899999886168731-------688408887246899999987


Q ss_pred             CCC
Q ss_conf             679
Q gi|254780277|r   83 NRP   85 (976)
Q Consensus        83 ~R~   85 (976)
T Consensus        94 R~~   96 (1127)
T TIGR00600        94 RRD   96 (1127)
T ss_pred             HHH
T ss_conf             653