Domain motions of glucosamine-6P synthase: comparison of the anisotropic displacements in the crystals and the catalytic hinge-bending rotation.

ABSTRACT: Glucosamine-6-phosphate synthase channels ammonia over 18 A from glutamine at the glutaminase site to fructose-6P at the synthase site. We have modeled the anisotropic displacements of the glutaminase and synthase domains from the two crystallized states, the enzyme in complex with fructose-6P or in complex with glucose-6P and a glutamine affinity analog, using TLS (rigid-body motion in terms of translation, libration, and screw motions) refinement implemented in REFMAC. The domains displacements in the crystal lattices are compared to the movement of the glutaminase domain relative to the synthase domain that occurs during the catalytic cycle upon glutamine binding, which was visualized by comparing the two structures. This movement was analyzed by the program DYNDOM as a 22.8 degrees rot

SUBMITTER: Mouilleron S 

PROVIDER: S-EPMC2203311 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature