A Comparison of Two Single-Stranded DNA Binding Models by Mutational Analysis of APOBEC3G.

ABSTRACT: APOBEC3G is the best known of several DNA cytosine deaminases that function to inhibit the replication of parasitic genetic elements including the lentivirus HIV. Several high-resolution structures of the APOBEC3G catalytic domain have been generated, but none reveal how this enzyme binds to substrate single-stranded DNA. Here, we constructed a panel of APOBEC3G amino acid substitution mutants and performed a series of biochemical, genetic, and structural assays to distinguish between "Brim" and "Kink" models for single-strand DNA binding. Each model predicts distinct sets of interactions between surface arginines and negatively charged phosphates in the DNA backbone. Concordant with both models, changing the conserved arginine at position 313 to glutamate abolished both catalytic and rest

SUBMITTER: Shindo K 

PROVIDER: S-EPMC4009770 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature