Structure of a CRISPR-associated protein Cas2 from Desulfovibrio vulgaris.

Publication Type:

Journal Article

Authors:

Samai, Poulami; Smith, Paul; Shuman, Stewart

Source:

Acta Crystallogr Sect F Struct Biol Cryst Commun, Volume 66, Issue Pt 12, p.1552-6 (2010)

Keywords:

Amino Acid Sequence, Bacterial Proteins, Catalytic Domain, Crystallography, X-Ray, Desulfovibrio vulgaris, Molecular Sequence Data, Phosphoric Diester Hydrolases, Protein Multimerization, Protein Structure, Secondary, Repetitive Sequences, Amino Acid, Sequence Homology, Amino Acid

Abstract:

<p>CRISPRs (clustered regularly interspaced short palindromic repeats) provide bacteria and archaea with RNA-guided acquired immunity to invasive DNAs. CRISPR-associated (Cas) proteins carry out the immune effector functions. Cas2 is a universal component of the CRISPR system. Here, a 1.35 Å resolution crystal structure of Cas2 from the bacterium Desulfovibrio vulgaris (DvuCas2) is reported. DvuCas2 is a homodimer, with each protomer consisting of an N-terminal βαββαβ ferredoxin fold (amino acids 1-78) to which is appended a C-terminal segment (amino acids 79-102) that includes a short 3(10)-helix and a fifth β-strand. The β5 strands align with the β4 strands of the opposite protomers, resulting in two five-stranded antiparallel β-sheets that form a sandwich at the dimer interface. The DvuCas2 dimer is stabilized by a distinctive network of hydrophilic cross-protomer side-chain interactions.</p>