Title : Crystal structure of human
intrinsic factor :
cobalamin complex at 2.6-A resolution
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
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*Output_Site_Fusion* (sent_index,
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