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.
Lee
Y H
YH
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235-8884, USA.
Deka
R K
RK
Norgard
M V
MV
Radolf
J D
JD
Hasemann
C A
CA
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