title: Solution structure of leptospiral LigA4 Big domain.
abstract: Pathogenic Leptospiraspecies express immunoglobulin-like proteins which serve as adhesins to bind to the extracellular matrices of host cells. Leptospiral immunoglobulin-like protein A (LigA), a surface exposed protein containing tandem repeats of bacterial immunoglobulin-like (Big) domains, has been proved to be involved in the interaction of pathogenic Leptospira with mammalian host. In this study, the solution structure of the fourth Big domain of LigA (LigA4 Big domain) from Leptospira interrogans was solved by nuclear magnetic resonance (NMR). The structure of LigA4 Big domain displays a similar bacterial immunoglobulin-like fold compared with other Big domains, implying some common structural aspects of Big domain family. On the other hand, it displays some structural characteristics significantly different from classic Ig-like domain. Furthermore, Stains-all assay and NMR chemical shift perturbation revealed the Ca(2+) binding property of LigA4 Big domain.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Song
authors.initials: S
authors.lastname: Mei
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
authors.forename: Jiahai
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Anhui University, Hefei, Anhui 230039, PR China.
authors.forename: Xuecheng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China. Electronic address: xmtu@ustc.edu.cn.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Tu
mesh_terms: D018829:Adhesins, Bacterial / Q000737:chemistry* / Q000235:genetics; D000595:Amino Acid Sequence; D002118:Calcium / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D007136:Immunoglobulins / Q000737:chemistry* / Q000235:genetics; D007921:Leptospira interrogans / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D018716:Molecular Mimicry; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D018829:Adhesins, Bacterial; D007136:Immunoglobulins; D011994:Recombinant Proteins; D002118:Calcium
keywords: Big domain; Ca(2+) binding; LigA; NMR