TY - JOUR
T1 - Insight into F plasmid DNA segregation revealed by structures of SopB and SopB-DNA complexes
AU - Schumacher, Maria A.
AU - Piro, Kevin M.
AU - Xu, Weijun
N1 - Funding Information:
M.D. Anderson Trust Fellowship, Burroughs Wellcome Career Development Award and the National Institutes of Health (GM074815 to M.A.S.). Funding for open access charge: National Institutes of Health.
Funding Information:
We thank the Advanced Light Source (ALS) and their support staff. The ALS is supported by the Director, Office of Science, Office of Basic Energy Sciences, and Material Science Division of the US Department of Energy at the Lawrence Berkeley National Laboratory.
PY - 2010/6/4
Y1 - 2010/6/4
N2 - Accurate DNA segregation is essential for genome transmission. Segregation of the prototypical F plasmid requires the centromere-binding protein SopB, the NTPase SopA and the sopC centromere. SopB displays an intriguing range of DNA-binding properties essential for partition; it binds sopC to form a partition complex, which recruits SopA, and it also coats DNA to prevent non-specific SopA-DNA interactions, which inhibits SopA polymerization. To understand the myriad functions of SopB, we determined a series of SopB-DNA crystal structures. SopB does not distort its DNA site and our data suggest that SopB-sopC forms an extended rather than wrapped partition complex with the SopA- interacting domains aligned on one face. SopB is a multidomain protein, which like P1 ParB contains an all-helical DNA-binding domain that is flexibly attached to a compact (β3-α)2 dimer-domain. Unlike P1 ParB, the SopB dimer-domain does not bind DNA. Moreover, SopB contains a unique secondary dimer- ization motif that bridges between DNA duplexes. Both specific and non-specific SopB-DNA bridging structures were observed. This DNA-linking function suggests a novel mechanism for in trans DNA spreading by SopB, explaining how it might mask DNA to prevent DNA-mediated inhibition of SopA polymerization.
AB - Accurate DNA segregation is essential for genome transmission. Segregation of the prototypical F plasmid requires the centromere-binding protein SopB, the NTPase SopA and the sopC centromere. SopB displays an intriguing range of DNA-binding properties essential for partition; it binds sopC to form a partition complex, which recruits SopA, and it also coats DNA to prevent non-specific SopA-DNA interactions, which inhibits SopA polymerization. To understand the myriad functions of SopB, we determined a series of SopB-DNA crystal structures. SopB does not distort its DNA site and our data suggest that SopB-sopC forms an extended rather than wrapped partition complex with the SopA- interacting domains aligned on one face. SopB is a multidomain protein, which like P1 ParB contains an all-helical DNA-binding domain that is flexibly attached to a compact (β3-α)2 dimer-domain. Unlike P1 ParB, the SopB dimer-domain does not bind DNA. Moreover, SopB contains a unique secondary dimer- ization motif that bridges between DNA duplexes. Both specific and non-specific SopB-DNA bridging structures were observed. This DNA-linking function suggests a novel mechanism for in trans DNA spreading by SopB, explaining how it might mask DNA to prevent DNA-mediated inhibition of SopA polymerization.
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U2 - 10.1093/nar/gkq161
DO - 10.1093/nar/gkq161
M3 - Article
C2 - 20236989
AN - SCOPUS:77955243507
SN - 0305-1048
VL - 38
SP - 4514
EP - 4526
JO - Nucleic acids research
JF - Nucleic acids research
IS - 13
M1 - gkq161
ER -