Catalytic activation of histone acetyltransferase Rtt109 by a histone chaperone.

ABSTRACT: Most histone acetyltransferases (HATs) function as multisubunit complexes in which accessory proteins regulate substrate specificity and catalytic efficiency. Rtt109 is a particularly interesting example of a HAT whose specificity and catalytic activity require association with either of two histone chaperones, Vps75 or Asf1. Here, we utilize biochemical, structural, and genetic analyses to provide the detailed molecular mechanism for activation of a HAT (Rtt109) by its activating subunit Vps75. The rate-determining step of the activated complex is the transfer of the acetyl group from acetyl CoA to the acceptor lysine residue. Vps75 stimulates catalysis (> 250-fold), not by contributing a catalytic base, but by stabilizing the catalytically active conformation of Rtt109. To provide struct

SUBMITTER: Kolonko EM 

PROVIDER: S-EPMC2996700 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature