TY - JOUR
T1 - Reconstitution of 5′-directed human mismatch repair in a purified system
AU - Zhang, Yanbin
AU - Yuan, Fenghua
AU - Presnell, Steven R.
AU - Tian, Keli
AU - Gao, Yin
AU - Tomkinson, Alan E.
AU - Gu, Liya
AU - Li, Guo Min
N1 - Funding Information:
We thank Ellen Fanning, Joe Jiricny, Mike Liskay, Carol Prives, Lene Rasmussen, Bruce Stillman, and Marc Wold for reagents. We also thank Peggy Hsieh, Tom Kunkel, Andrew Pierce, and Jean Wang for helpful comments; Richard Kolodner for sharing unpublished results; and two anonymous reviewers for detailed and insightful critiques. This work was supported in part by NIH grants ES013193 and CA85377 (to G.-M.L.), CA104333 (to L.G.), and GM57479 (to A.E.T.) and a grant from the Kentucky Lung Cancer Research Program (to G.-M.L.). G.-M.L. is a James-Gardner Chair in Cancer Research.
PY - 2005/9/9
Y1 - 2005/9/9
N2 - This paper reports reconstitution of 5′-nick-directed mismatch repair using purified human proteins. The reconstituted system includes MutSα or MutSβ, MutLα, RPA, EXO1, HMGB1, PCNA, RFC, polymerase δ, and ligase I. In this system, MutSβ plays a limited role in repair of base-base mismatches, but it processes insertion/deletion mispairs much more efficiently than MutSα, which efficiently corrects both types of heteroduplexes. MutLα reduces the processivity of EXO1 and terminates EXO1-catalyzed excision upon mismatch removal. In the absence of MutLα, mismatch-provoked excision by EXO1 occurs extensively. RPA and HMGB1 play similar but complementary roles in stimulating MutSα-activated, EXO1-catalyzed excision in the presence of a mismatch, but RPA has a distinct role in facilitating MutLα-mediated excision termination past mismatch. Evidence is provided that efficient repair of a single mismatch requires multiple molecules of MutSα-MutLα complex. These data suggest a model for human mismatch repair involving coordinated initiation and termination of mismatch-provoked excision.
AB - This paper reports reconstitution of 5′-nick-directed mismatch repair using purified human proteins. The reconstituted system includes MutSα or MutSβ, MutLα, RPA, EXO1, HMGB1, PCNA, RFC, polymerase δ, and ligase I. In this system, MutSβ plays a limited role in repair of base-base mismatches, but it processes insertion/deletion mispairs much more efficiently than MutSα, which efficiently corrects both types of heteroduplexes. MutLα reduces the processivity of EXO1 and terminates EXO1-catalyzed excision upon mismatch removal. In the absence of MutLα, mismatch-provoked excision by EXO1 occurs extensively. RPA and HMGB1 play similar but complementary roles in stimulating MutSα-activated, EXO1-catalyzed excision in the presence of a mismatch, but RPA has a distinct role in facilitating MutLα-mediated excision termination past mismatch. Evidence is provided that efficient repair of a single mismatch requires multiple molecules of MutSα-MutLα complex. These data suggest a model for human mismatch repair involving coordinated initiation and termination of mismatch-provoked excision.
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U2 - 10.1016/j.cell.2005.06.027
DO - 10.1016/j.cell.2005.06.027
M3 - Article
C2 - 16143102
AN - SCOPUS:24144447320
SN - 0092-8674
VL - 122
SP - 693
EP - 705
JO - Cell
JF - Cell
IS - 5
ER -