5B58

Inward-facing conformation of ABC heme importer BhuUV in complex with periplasmic heme binding protein BhuT from Burkholderia cenocepacia

Summary for 5B58

• Entry DOI: 10.2210/pdb5b58/pdb
• Related: 5B57
• Descriptor: Putative hemin ABC transport system, membrane protein, Hemin import ATP-binding protein HmuV, Putative hemin transport system, substrate-binding protein (3 entities in total)
• Functional Keywords: metal-binding, metal binding protein
• Biological source: Burkholderia cenocepacia J2315; More
• Total number of polymer chains: 5
• Total formula weight: 164084.01

Authors

Naoe, Y.,Nakamura, N.,Doi, A.,Shiro, Y.,Sugimoto, H. (deposition date: 2016-04-25, release date: 2016-11-23, Last modification date: 2023-11-08)

Primary citation

Naoe, Y.,Nakamura, N.,Doi, A.,Sawabe, M.,Nakamura, H.,Shiro, Y.,Sugimoto, H.
Crystal structure of bacterial haem importer complex in the inward-facing conformation
Nat Commun, 7:13411-13411, 2016

PubMed Abstract: Pathogenic bacteria remove iron from the haem of host tissues and use it as a catalytic center of many enzymes. Haem uptake by pathogenic bacteria is facilitated by the membrane-integrated haem importer, which belongs to the type II ATP-binding cassette (ABC) transporter. Here we present crystal structures of Burkholderia cenocepacia haem importer BhuUV complexed with the periplasmic haem-binding protein BhuT and in the absence of BhuT. The transmembrane helices of these structures show an inward-facing conformation, in which the cytoplasmic gate of the haem translocation pathway is completely open. Since this conformation is found in both the haem- and nucleotide-free form, the structure of BhuUV-T provides the post-translocation state and the missing piece in the transport cycle of the type II importer. Structural comparison with the outward-facing conformation reported for the haem importer ortholog HmuUV from Yersenia pestis gives mechanistic insights into conformational transitions and haem secretion during the haem transport cycle.

PubMed: 27830695
DOI: 10.1038/ncomms13411

Experimental method

X-RAY DIFFRACTION (3.21 Å)