期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2002
卷号：99
期号：6
页码：3434-3439
DOI：10.1073/pnas.052017999
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The integrase protein (Int) from bacteriophage {lambda} catalyzes the insertion and excision of the viral genome into and out of Escherichia coli. It is a member of the {lambda}-Int family of site-specific recombinases that catalyze a diverse array of DNA rearrangements in archaebacteria, eubacteria, and yeast and belongs to the subset of this family that possesses two autonomous DNA-binding domains. The heterobivalent properties of Int can be decomposed into a carboxyl-terminal domain that executes the DNA cleavage and ligation reactions and a smaller amino-terminal domain that binds to an array of conserved DNA sites within the phage arms, thereby arranging Int protomers within the higher-order recombinogenic complex. We have determined that residues Met-1 to Leu-64 of Int constitute the minimal arm-type DNA-binding domain (INT-DBD1-64) and solved the solution structure by using NMR. We show that the INT-DBD1-64 is a novel member of the growing family of three-stranded {beta}-sheet DNA-binding proteins, because it supplements this motif with a disordered amino-terminal basic tail that is important for arm-site binding. A model of the arm-DNA-binding domain recognizing its cognate DNA site is proposed on the basis of similarities with the analogous domain of Tn916 Int and is discussed in relation to other features of the protein.
