1guo
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MOPII FROM CLOSTRIDIUM PASTEURIANUM COMPLEXED WITH MOLYBDATE
OverviewOverview
MopII from Clostridium pasteurianum is a molbindin family member. These, proteins may serve as intracellular storage facilities for molybdate, which they bind with high specificity. High resolution structures of MopII, in a number of states, including the first structure of an apo-molbindin, together with calorimetric data, allow us to describe ligand binding and, provide support for the proposed storage function of the protein. MopII, assembles as a trimer of dimers and binds eight oxyanions at two types of, binding sites located at intersubunit interfaces. Two type 1 sites are on, the molecular 3-fold axis and three pairs of type 2 sites occur on the, molecular 2-fold axes. The hexamer is largely unaffected by the binding of, ligand. Molybdate is admitted to the otherwise inaccessible type 2 binding, sites by the movement of the N-terminal residues of each protein chain., This contrasts with the structurally related molybdate-dependent, transcriptional regulator ModE, which undergoes extensive conformational, rearrangements on ligand binding. Despite similarities between the binding, sites of ModE and the type 2 sites of MopII the molbindin has a, significantly reduced ligand affinity, due, in part, to the high density, of negative charges at the center of the hexamer. In the absence of ligand, this effects the movement of an important lysine side chain, thereby, partially inactivating the binding sites. The differences are consistent, with a biological role in molybdate storage/buffering.
About this StructureAbout this Structure
1GUO is a Single protein structure of sequence from Clostridium pasteurianum with MOO as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Passive acquisition of ligand by the MopII molbindin from Clostridium pasteurianum: structures of apo and oxyanion-bound forms., Schuttelkopf AW, Harrison JA, Boxer DH, Hunter WN, J Biol Chem. 2002 Apr 26;277(17):15013-20. Epub 2002 Feb 8. PMID:11836258
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