Structural highlights
Function
[BTUC_ECOLI] Part of the ABC transporter complex BtuCDF involved in vitamin B12 import. Involved in the translocation of the substrate across the membrane.[HAMAP-Rule:MF_01004] [BTUF_ECOLI] Part of the ABC transporter complex BtuCDF involved in vitamin B12 import. Binds vitamin B12 and delivers it to the periplasmic surface of BtuC.[1] [BTUD_ECOLI] Part of the ABC transporter complex BtuCDF involved in vitamin B12 import. Responsible for energy coupling to the transport system (By similarity).
Publication Abstract from PubMed
BtuCD is an ABC transporter catalyzing the uptake of vitamin B(12) across the Escherichia coli inner membrane. A previously reported X-ray structure of BtuCD in complex with the periplasmic vitamin B(12)-binding protein BtuF revealed asymmetry of the transmembrane BtuC subunits. The functional relevance of this asymmetry has remained uncertain. Here we report the X-ray structure of a catalytically impaired BtuCD mutant in complex with BtuF, where the BtuC subunits adopt a distinct asymmetric conformation. The structure suggests that BtuF does not discriminate between, or impose, asymmetric conformations of BtuCD. It also explains the conformational disorder observed in BtuCDF crystals.
Asymmetric states of vitamin B12 transporter BtuCD are not discriminated by its cognate substrate binding protein BtuF.,Korkhov VM, Mireku SA, Hvorup RN, Locher KP FEBS Lett. 2012 Apr 5;586(7):972-6. Epub 2012 Mar 8. PMID:22569249[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Cadieux N, Bradbeer C, Reeger-Schneider E, Koster W, Mohanty AK, Wiener MC, Kadner RJ. Identification of the periplasmic cobalamin-binding protein BtuF of Escherichia coli. J Bacteriol. 2002 Feb;184(3):706-17. PMID:11790740
- ↑ Korkhov VM, Mireku SA, Hvorup RN, Locher KP. Asymmetric states of vitamin B12 transporter BtuCD are not discriminated by its cognate substrate binding protein BtuF. FEBS Lett. 2012 Apr 5;586(7):972-6. Epub 2012 Mar 8. PMID:22569249 doi:10.1016/j.febslet.2012.02.042
