Publication Date:
2019
Description:
〈p〉ParABS systems facilitate chromosome segregation and plasmid partitioning in bacteria and archaea. ParB protein binds centromeric 〈i〉parS〈/i〉 DNA sequences and spreads to flanking DNA. We show that ParB is an enzyme that hydrolyzes cytidine triphosphate (CTP) to cytidine diphosphate (CDP). 〈i〉parS〈/i〉 DNA stimulates cooperative CTP binding by ParB and CTP hydrolysis. A nucleotide cocrystal structure elucidates the catalytic center of the dimerization-dependent ParB CTPase. Single-molecule imaging and biochemical assays recapitulate features of ParB spreading from 〈i〉parS〈/i〉 in the presence but not absence of CTP. These findings suggest that centromeres assemble by self-loading of ParB DNA sliding clamps at 〈i〉parS〈/i〉. ParB CTPase is not related to known nucleotide hydrolases and might be a promising target for developing new classes of antibiotics.〈/p〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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