BIOMOLECULE: 1 THE BIOLOGICALLY RELEVANT MOLECULE OF FULL-LENGTH CORA IS A HOMOPENTAMER. HERE, WE ... BIOMOLECULE: 1 THE BIOLOGICALLY RELEVANT MOLECULE OF FULL-LENGTH CORA IS A HOMOPENTAMER. HERE, WE FIND A SINGLE MOLECULE OF THE SOLUBLE DOMAIN WITHIN THE ASSYMETRIC UNIT, AND A DOMAIN-SWAPPED DIMER IS FORMED BY SPACE GROUP SYMMETRY. WE HAVE PROPOSED THAT THE CONFORMATIONAL CHANGE OBSERVED HERE, RELATIVE TO THE FULL-LENGTH PROTEIN, MAY INDICATE A MECHANISM FOR GATING IN THE FULL-LENGTH TRANSPORTER PROTEIN.
The biologically relavent molecule of CorA is a pentamer. A single chain is observed in the assymetric unit, and a domain-swapped dimer is formed by space group symmetry. When compared to other known structures of CorA, the conformational changes observed in this soluble domain structure may indicate a mechanism for activation (i.e. CorA gating). Alternatively, the conformation observed could be a cloning and/or crystallization artifact. The Co2+ coordinated to Asp253 and His257 was confirmed experimentally by solving this structure independently from a MAD experiment (performed on a native crystal) at the cobalt absorption edge.