Functional clues from the crystal structure of an orphan periplasmic ligand-binding protein from Treponema pallidum.
The spirochete Treponema pallidum is the causative agent of syphilis, a sexually transmitted infection of major global importance. Other closely related subspecies of Treponema also are the etiological agents of the endemic treponematoses, such as yaws, pinta, and bejel. The inability of T. pallidum and its close relatives to be cultured in vitro has prompted efforts to characterize T. pallidum's proteins structurally and biophysically, particularly those potentially relevant to treponemal membrane biology, with the goal of possibly revealing the functions of those proteins. This report describes the structure of the treponemal protein Tp0737; this polypeptide has a fold characteristic of a class of periplasmic ligand-binding proteins associated with ABC-type transporters. Although no ligand for the protein was observed in electron-density maps, and thus the nature of the native ligand remains obscure, the structural data described herein provide a foundation for further efforts to elucidate the ligand and thus the function of this protein in T. pallidum.
Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.|Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
Chad A
CA
Brautigam
Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
Ranjit K
RK
Deka
Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
Wei Z
WZ
Liu
Department of Biophysics, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.|Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
Diana R
DR
Tomchick
Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, Texas, 75390.
Michael V
MV
Norgard
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D033903:Periplasmic Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000072417:Protein Domains; D013329:Structure-Activity Relationship; D014210:Treponema pallidum / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D033903:Periplasmic Proteins
ABC transporter; X-ray crystallography; analytical ultracentrifugation; differential scanning fluorimetry; syphilis