Summary information and primary citation
- PDB-id
-
1ixy;
DSSR-derived features in text and
JSON formats
- Class
- transferase-DNA
- Method
- X-ray (2.5 Å)
- Summary
- Ternary complex of t4 phage bgt with udp and a 13 mer
DNA duplex
- Reference
-
Lariviere L, Morera S (2002): "A
Base-flipping Mechanism for the T4 Phage
beta-Glucosyltransferase and Identification of a
Transition-state Analog." J.Mol.Biol.,
324, 483-490. doi: 10.1016/S0022-2836(02)01091-4.
- 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.
