title: Crystal structure of a putative oligopeptide-binding periplasmic protein from a hyperthermophile.
abstract: Oligopeptide-binding proteins (Opps) are part of the ATP-binding cassette system, playing a crucial role in nutrient uptake and sensing the external environment in bacteria, including hyperthermophiles. Opps serve as a binding platform for diverse peptides; however, how these peptides are recognized by Opps is still largely unknown and few crystal structures of Opps from hyperthermophiles have been determined. To facilitate such an understanding, the crystal structure of a putative Opp, OppA from Thermotoga maritima (TmOppA), was solved at 2.6-Å resolution in the open conformation. TmOppA is composed of three domains. The N-terminal domain consists of twelve strands, nine helices, and four 310 helices, and the C-terminal domain consists of five strands, ten helices, and one 310 helix. These two domains are connected by the linker domain, which consists of two strands, three helices, and three 310 helices. Based on structural comparisons of TmOppA with other OppAs and binding studies, we suggest that TmOppA might be a periplasmic Opp. The most distinct feature of TmOppA is the insertion of two helices, which are lacking in other OppAs. A cavity volume between the N-terminal and C-terminal domains is suggested to be responsible for binding peptides of various lengths.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Yoon
authors.affiliation: Department of Bio and Nano Chemistry, Kookmin University, Seoul, 136-702, Korea.
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Laboratory of Quality Design and Exploitation, Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Kyoto, 611-0011, Japan.
authors.forename: Bunzo
authors.initials: B
authors.lastname: Mikami
authors.affiliation: Department of Bio and Nano Chemistry, Kookmin University, Seoul, 136-702, Korea.
authors.forename: Yeon Gyu
authors.initials: YG
authors.lastname: Yu
authors.affiliation: Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 151-742, Korea. Hyungholee@snu.ac.kr.
authors.forename: Hyung Ho
authors.initials: HH
authors.lastname: Lee
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D020816:Amino Acid Motifs; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008074:Lipoproteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D019897:Periplasm / Q000378:metabolism*; D011485:Protein Binding; D020124:Thermotoga maritima / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D008074:Lipoproteins; C046506:oligopeptide-binding protein, bacteria; D000255:Adenosine Triphosphate
keywords: Hyperthermophile; Oligopeptide ABC transporter; OppA; Thermotoga maritima