4dks

Publication Abstract from PubMed

The spindle-shaped virus SSV1 of the hyperthermophilic archaeon Sulfolobus shibatae encodes an integrase (SSV1 Int). Here, the crystal structure of the C-terminal catalytic domain of SSV1 Int is reported. This is the first structural study of an archaeal tyrosine recombinase. Structural comparison shows that the C-terminal domain of SSV1 Int possesses a core fold similar to those of tyrosine recombinases of both bacterial and eukaryal origin, apart from the lack of a conserved helix corresponding to alphaI of Cre, indicating conservation of these enzymes among all three domains of life. Five of the six catalytic residues cluster around a basic cleft on the surface of the structure and the nucleophile Tyr314 is located on a flexible loop that stretches away from the central cleft, supporting the possibility that SSV1 Int cleaves the target DNA in a trans mode. Biochemical analysis suggests that the N-terminal domain is responsible for the dimerization of SSV1 Int. The C-terminal domain is capable of DNA cleavage and ligation, but at efficiencies significantly lower than those of the full-length protein. In addition, neither the N-terminal domain alone nor the C-terminal domain alone shows a strong sequence preference in DNA binding. Therefore, recognition of the core-type sequence and efficient catalysis by SSV1 Int presumably requires covalent linkage and interdomain communication between the two domains.

Structural and functional characterization of the C-terminal catalytic domain of SSV1 integrase.,Zhan Z, Ouyang S, Liang W, Zhang Z, Liu ZJ, Huang L Acta Crystallogr D Biol Crystallogr. 2012 Jun;68(Pt 6):659-70. doi:, 10.1107/S0907444912007202. Epub 2012 May 17. PMID:22683788^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.