Human Rad50/Mre11 is a flexible complex that can tether DNA ends.
The human Rad50 protein, classified as a structural maintenance of chromosomes (SMC) family member, is complexed with Mre11 (R/M) and has important functions in at least two distinct double-strand break repair pathways. To find out what the common function of R/M in these pathways might be, we investigated its architecture. Scanning force microscopy showed that the complex architecture is distinct from the described SMC family members. R/M consisted of two highly flexible intramolecular coiled coils emanating from a central globular DNA binding domain. DNA end-bound R/M oligomers could tether linear DNA molecules. These observations suggest that a unified role for R/M in multiple aspects of DNA repair and chromosome metabolism is to provide a flexible, possibly dynamic, link between DNA ends.
de Jager
M
M
Department of Cell Biology and Genetics, Erasmus University Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, Rotterdam, The Netherlands.
van Noort
J
J
van Gent
D C
DC
Dekker
C
C
Kanaar
R
R
Wyman
C
C
D004247:DNA / Q000378:metabolism*; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D000076228:MRE11 Homologue Protein; D046911:Macromolecular Substances; D018625:Microscopy, Atomic Force; D017434:Protein Structure, Tertiary; D029701:Saccharomyces cerevisiae Proteins
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C121766:MRE11 protein, human; D046911:Macromolecular Substances; C086930:RAD50 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D004247:DNA; D000076228:MRE11 Homologue Protein