Two crystal forms of the restriction enzyme MspI-DNA complex show the same novel structure.

ABSTRACT: The crystal structure of the Type IIP restriction endonuclease MspI bound to DNA containing its cognate recognition sequence has been determined in both monoclinic and orthorhombic space groups. Significantly, these two independent crystal forms present an identical structure of a novel monomer-DNA complex, suggesting a functional role for this novel enzyme-DNA complex. In both crystals, MspI interacts with the CCGG DNA recognition sequence as a monomer, using an asymmetric mode of recognition by two different structural motifs in a single polypeptide. In the crystallographic asymmetric unit, the two DNA molecules in the two MspI-DNA complexes appear to stack with each other forming an end-to-end pseudo-continuous 19-mer duplex. They are primarily B-form and no major bends or kinks are obs

SUBMITTER: Xu QS 

PROVIDER: S-EPMC2253285 | biostudies-literature | 2005 Oct

REPOSITORIES: biostudies-literature