Functional properties of the thermostable mutL from Thermotoga maritima.
The methyl-directed mismatch repair (MMR) mechanism has been extensively studied in vitro and in vivo, but one of the difficulties in determining the biological relationships between the MMR-related proteins is the tendency of MutL to self-aggregate. The properties of a stable MutL homologue were investigated using a thermostable MutL (TmL) from Thermotoga maritima MSB8 and whose size exclusion chromatographic and crosslinking analyses were compatible with a dimeric form of TmL. TmL underwent conformational changes in the presence of nucleotides and single-stranded DNA (ssDNA) with ATP binding not requiring ssDNA binding activity of TmL, while ADPnP-stimulated TmL showed a high ssDNA binding affinity. Finally, TmL interacted with the T. maritima MutS (TmS), increasing the affinity of TmS to mismatched DNA base pairs and suggesting that the role of TmL in the formation of a mismatched DNA-TmS complex may be a pivotal observation for the study of the initial MMR system. [BMB reports 2009; 42(1): 53-58].
Kim
Tae Gyun
TG
Department of Chemistry, Pohang University of Science and Technology, Pohang 790-784, Korea.
Heo
Seong-Dal
SD
Ku
Ja Kang
JK
Ban
Changill
C
D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D020137:Base Pair Mismatch / Q000187:drug effects; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004269:DNA, Bacterial / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D006868:Hydrolysis / Q000187:drug effects; D007700:Kinetics; D050505:Mutant Proteins / Q000378:metabolism; D009711:Nucleotides / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D055503:Protein Multimerization / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D013696:Temperature; D020124:Thermotoga maritima / Q000187:drug effects / Q000378:metabolism*
D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D050505:Mutant Proteins; D009711:Nucleotides; D000255:Adenosine Triphosphate