4dwl

Publication Abstract from PubMed

Diversity-generating retroelements (DGRs) are the only known source of massive protein sequence variation in prokaryotes. These elements transfer coding information from a template region (TR) through an RNA intermediate to a protein-encoding variable region. This retrohoming process is accompanied by unique adenine-specific mutagenesis and, in the prototypical BPP-1 DGR, requires a reverse transcriptase (bRT) and an accessory variability determinant (bAvd) protein. To understand the role of bAvd, we determined its 2.69 A resolution structure, which revealed a highly positively charged pentameric barrel. In accordance with its charge, bAvd bound both DNA and RNA, albeit without a discernable sequence preference. We found that the coding sequence of bAvd functioned as part of TR but identified means to mutate bAvd without affecting TR. This mutational analysis revealed a strict correspondence between retrohoming and interaction of bAvd with bRT, suggesting that the bRT-bAvd complex is important for DGR retrohoming.

Structure of the essential diversity-generating retroelement protein bAvd and its functionally important interaction with reverse transcriptase.,Alayyoubi M, Guo H, Dey S, Golnazarian T, Brooks GA, Rong A, Miller JF, Ghosh P Structure. 2013 Feb 5;21(2):266-76. doi: 10.1016/j.str.2012.11.016. Epub 2012 Dec, 27. PMID:23273427^[1]

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