2PMV

Crystal Structure of Human Intrinsic Factor- Cobalamin Complex at 2.6 A Resolution

Summary for 2PMV

• Entry DOI: 10.2210/pdb2pmv/pdb
• Descriptor: Gastric intrinsic factor, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, COBALAMIN, ... (4 entities in total)
• Functional Keywords: cobalamin transport protein alpha6-alpha6 motif two domain protein, transport protein
• Biological source: Homo sapiens (human)
• Cellular location: Secreted: P27352
• Total number of polymer chains: 4
• Total formula weight: 177303.03

Authors

Mathews, F.S.,Gordon, M.M.,Chen, Z.,Rajashankar, K.R.,Ealick, S.E.,Alpers, D.H.,Sukumar, N. (deposition date: 2007-04-23, release date: 2007-10-30, Last modification date: 2024-10-16)

Primary citation

Mathews, F.S.,Gordon, M.M.,Chen, Z.,Rajashankar, K.R.,Ealick, S.E.,Alpers, D.H.,Sukumar, N.
Crystal structure of human intrinsic factor: Cobalamin complex at 2.6-A resolution
Proc.Natl.Acad.Sci.USA, 104:17311-17316, 2007

PubMed Abstract: The structure of intrinsic factor (IF) in complex with cobalamin (Cbl) was determined at 2.6-A resolution. The overall fold of the molecule is that of an alpha(6)/alpha(6) barrel. It is a two-domain protein, and the Cbl is bound at the interface of the domains in a base-on conformation. Surprisingly, two full-length molecules, each comprising an alpha- and a beta-domain and one Cbl, and two truncated molecules with only an alpha- domain are present in the same asymmetric unit. The environment around Cbl is dominated by uncharged residues, and the sixth coordinate position of Co(2+) is empty. A detailed comparison between the IF-B12 complex and another Cbl transport protein complex, trans-Cbl-B12, has been made. The pH effect on the binding of Cbl analogues in transport proteins is analyzed. A possible basis for the lack of interchangeability of human and rat IF receptors is presented.

PubMed: 17954916
DOI: 10.1073/pnas.0703228104

Experimental method

X-RAY DIFFRACTION (2.6 Å)