Download MendeleyA Base-flipping mechanism for the T4 phage beta-glucosyltransferase and identification of a transition state analog
Lariviere, L., Morera, S.(2002) J Mol Biol 324: 483-489
- PubMed: 12445783
- DOI: https://doi.org/10.1016/s0022-2836(02)01091-4
- Primary Citation of Related Structures:
1IXY, 1M5R - PubMed Abstract:
T4 phage beta-glucosyltransferase (BGT) modifies T4 DNA. We crystallized BGT with UDP-glucose and a 13mer DNA fragment containing an abasic site. We obtained two crystal structures of a ternary complex BGT-UDP-DNA at 1.8A and 2.5A resolution, one with a Tris molecule and the other with a metal ion at the active site. Both structures reveal a large distortion in the bound DNA. BGT flips the deoxyribose moiety at the abasic site to an extra-helical position and induces a 40 degrees bend in the DNA with a marked widening of the major groove. The Tris molecule mimics the glucose moiety in its transition state. The base-flipping mechanism, which has so far been observed only for glycosylases, methyltransferases and endonucleases, is now reported for a glucosyltransferase. BGT is unique in binding and inserting a loop into the DNA duplex through the major groove only. Furthermore, BGT compresses the backbone DNA one base further than the target base on the 3'-side.
Organizational Affiliation:
Laboratoire d'Enzymologie et Biochimie Structurales, UPR 9063 CNRS, Bât. 34, 1 Avenue de la Terrasse, 91198, Gif-sur-Yvette, France
