tailieunhanh - Báo cáo khoa học: DNA mismatch repair system Classical and fresh roles

The molecular mechanisms of the DNA mismatch repair (MMR) system have been uncovered over the last decade, especially in prokaryotes. The results obtained for prokaryotic MMR proteins have provided a frame-work for the study of the MMR system in eukaryotic organisms, such as yeast, mouse and human, because the functions of MMR proteins have been conserved during evolution from bacteria to humans. | ềFEBS Journal MINIREVIEW DNA mismatch repair system Classical and fresh roles Sung-Hoon Jun Tae Gyun Kim and Changill Ban Department of Chemistry and Division of Molecular Life Science Pohang University of Science and Technology Korea Key words antibody diversification DNA damage response DNA mismatch repair MutL MutS Correspondence C. Ban Department of Chemistry Pohang University of Science and Technology Pohang 790-784 Korea Fax 82 54 2793399 Tel 82 54 2792127 E-mail ciban@ Received 12 December 2005 accepted 10 February 2006 The molecular mechanisms of the DNA mismatch repair MMR system have been uncovered over the last decade especially in prokaryotes. The results obtained for prokaryotic MMR proteins have provided a framework for the study of the MMR system in eukaryotic organisms such as yeast mouse and human because the functions of MMR proteins have been conserved during evolution from bacteria to humans. However mutations in eukaryotic MMR genes result in pleiotropic phenotypes in addition to MMR defects suggesting that eukaryotic MMR proteins have evolved to gain more diverse and specific roles in multicellular organisms. Here we summarize recent advances in the understanding of both prokaryotic and eukaryotic MMR systems and describe various new functions of MMR proteins that have been intensively researched during the last few years including DNA damage surveillance and diversification of antibodies. doi The mismatch repair MMR system is essential to all organisms because it maintains the stability of the genome during repeated duplication. It is composed of a few well-conserved proteins whose functions in the postreplicative repair of mismatched DNA have been characterized by co-ordinated genetic biochemical and structural approaches. Various functions in addition to mismatch repair during replication have been reported for MMR proteins such as antirecombination activity between divergent sequences promotion