title: Crystal structure of CagL from Helicobacter pylori K74 strain.
abstract: Helicobacter pylori (Hp) CagL is a component of the type IV secretion system (T4SS) and interacts with integrin in host cells through its flexible RGD domain to translocate CagA. Differences in CagL amino acid polymorphisms between Western and East-Asian Hps are correlated with clinical outcome. CagL of East-Asian clinical Hp isolate K74 (CagL(K74)) contains multiple residue variations upstream of RGD motif and has different integrin binding affinities compared to those of CagL from Western Hp 26695. Here, we report the crystal structure of CagL(K74). The structure displayed a six-helix bundle including two short α-helices, and the RGD motif was found in the long rigid α2 helix flanked by the conserved protease-sensitive and RGD-helper sequences, as observed in CagL(26695). However, two additional salt bridges were found between the helices compared with the CagL(26695) structure, suggesting that the putative flexible region harboring the RGD motif may be more stable in this CagL variant.
authors.affiliation: Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju 501-759, Republic of Korea.
authors.forename: Jin Myung
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Department of Applied Life Science, The Graduate School, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul 120-752, Republic of Korea.
authors.forename: Yun Hui
authors.initials: YH
authors.lastname: Choi
authors.affiliation: Department of Bio-Materials, Graduate School, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Muddenahalli Srinivasa
authors.initials: MS
authors.lastname: Sudhanva
authors.affiliation: Department of Bio-Materials, Graduate School, Chosun University, Gwangju 501-759, Republic of Korea.
authors.forename: Sundaravinayagam
authors.initials: S
authors.lastname: Devakumar
authors.affiliation: Department of Biomedical Sciences, College of Natural Sciences, Gwangju 501-759, Republic of Korea.
authors.forename: Kun Ho
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Department of Applied Life Science, The Graduate School, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul 120-752, Republic of Korea. Electronic address: jcha@yuhs.ac.
authors.forename: Jeong-Heon
authors.initials: JH
authors.lastname: Cha
authors.affiliation: Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju 501-759, Republic of Korea. Electronic address: sunglee@chosun.ac.kr.
authors.forename: Sung Haeng
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D016480:Helicobacter pylori / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
chemical_list: D001426:Bacterial Proteins; C568315:cagL protein, Helicobacter pylori
keywords: CagL; Helicobacter pylori; Protein structure; RGD domain; T4SS