Treponema pallidum TroA is a periplasmic zinc-binding protein with a helical backbone.
The crystal structure of recombinant TroA, a zinc-binding protein component of an ATP-binding cassette transport system in Treponema pallidum, was determined at a resolution of 1.8 A. The organization of the protein is largely similar to other periplasmic ligand-binding proteins (PLBP), in that two independent globular domains interact with each other to create a zinc-binding cleft between them. The structure has one bound zinc pentavalently coordinated to residues from both domains. Unlike previous PLBP structures that have an interdomain hinge composed of beta-strands, the N- and C-domains of TroA are linked by a single long backbone helix. This unique backbone helical conformation was possibly adopted to limit the hinge motion associated with ligand exchange.
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8884, USA.
Y H
YH
Lee
R K
RK
Deka
M V
MV
Norgard
J D
JD
Radolf
C A
CA
Hasemann
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry; D029968:Escherichia coli Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019897:Periplasm / Q000737:chemistry*; D033902:Periplasmic Binding Proteins; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry; D045331:Photosystem I Protein Complex; D017433:Protein Structure, Secondary; D014210:Treponema pallidum / Q000737:chemistry*; D014961:X-Ray Diffraction; D015032:Zinc / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C461619:MalE protein, E coli; C073973:PSI-A protein, Synechococcus; D033902:Periplasmic Binding Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex; C120377:TroA protein, Treponema pallidum; D015032:Zinc