The GyrA-box determines the geometry of DNA bound to gyrase and couples DNA binding to the nucleotide cycle.

ABSTRACT: DNA gyrase catalyses the adenosine triphosphate-dependent introduction of negative supercoils into DNA. The enzyme binds a DNA-segment at the so-called DNA-gate and cleaves both DNA strands. DNA extending from the DNA-gate is bound at the perimeter of the cylindrical C-terminal domains (CTDs) of the GyrA subunit. The CTDs are believed to contribute to the wrapping of DNA around gyrase in a positive node as a prerequisite for strand passage towards negative supercoiling. A conserved seven amino acid sequence motif in the CTD, the so-called GyrA-box, has been identified as a hallmark feature of gyrases. Mutations of the GyrA-box abolish supercoiling. We show here that the GyrA-box marginally stabilizes the CTDs. Although it does not contribute to DNA binding, it is required for DNA bending a

SUBMITTER: Lanz MA 

PROVIDER: S-EPMC3510516 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature