Protein Science, Vol 3, Issue 1 64-69, Copyright © 1994 by Cold Spring Harbor Laboratory Press

ARTICLE

Crystal structure of the unactivated ribulose 1,5-bisphosphate carboxylase/oxygenase complexed with a transition state analog, 2-carboxy-D-arabinitol 1,5-bisphosphate

KYJ. ZHANG, D. CASCIO and D. EISENBERG
Molecular Biology Institute and Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90024-1570

The crystal structure of unactivated ribulose 1,5-bisphosphate carboxylase/oxygenase from Nicotiana tabacum complexed with a transition state analog, 2-carboxy-D-arabinitol 1,5-bisphosphate, was determined to 2.7 resolution by X-ray crystallography. The transition state analog binds at the active site in an extended conformation. As compared to the binding of the same analog in the activated enzyme, the analog binds in a reverse orientation. The active site Lys 201 is within hydrogen bonding distance of the carboxyl oxygen of the analog. Loop 6 (residues 330-339) remains open and flexible upon binding of the analog in the unactivated enzyme, in contrast to the closed and ordered loop 6 in the activated enzyme complex. The transition state analog is exposed to solvent due to the open conformation of loop 6.
CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?