TY  - JOUR
A1  - Plotz, Guido
A1  - Raedle, Jochen
A1  - Brieger, Angela
A1  - Trojan, Jörg
A1  - Zeuzem, Stefan
T1  - N‐terminus of hMLH1 confers interaction of hMutLα and hMutLβ with hMutSα
T2  - Nucleic acids research
N2  - Mismatch repair is a highly conserved system that ensures replication fidelity by repairing mispairs after DNA synthesis. In humans, the two protein heterodimers hMutSα (hMSH2‐hMSH6) and hMutLα (hMLH1‐hPMS2) constitute the centre of the repair reaction. After recognising a DNA replication error, hMutSα recruits hMutLα, which then is thought to transduce the repair signal to the excision machinery. We have expressed an ATPase mutant of hMutLα as well as its individual subunits hMLH1 and hPMS2 and fragments of hMLH1, followed by examination of their interaction properties with hMutSα using a novel interaction assay. We show that, although the interaction requires ATP, hMutLα does not need to hydrolyse this nucleotide to join hMutSα on DNA, suggesting that ATP hydrolysis by hMutLα happens downstream of complex formation. The analysis of the individual subunits of hMutLα demonstrated that the hMutSα–hMutLα interaction is predominantly conferred by hMLH1. Further experiments revealed that only the N‐terminus of hMLH1 confers this interaction. In contrast, only the C‐terminus stabilised and co‐immunoprecipitated hPMS2 when both proteins were co‐expressed in 293T cells, indicating that dimerisation and stabilisation are mediated by the C‐terminal part of hMLH1. We also examined another human homologue of bacterial MutL, hMutLβ (hMLH1–hPMS1). We show that hMutLβ interacts as efficiently with hMutSα as hMutLα, and that it predominantly binds to hMutSα via hMLH1 as well.
Y1  - 2006
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/2142
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-32700
SN  - 1362-4962
SN  - 0305-1048
N1  - © Oxford University Press 2003; all rights reserved
VL  - 31
IS  - 12
SP  - 3217
EP  - 3226
PB  - Oxford Univ. Press
CY  - Oxford
ER  -