title: Expression, purification, crystallization and structure determination of the N terminal domain of Fhb, a factor H binding protein from Streptococcus suis.
abstract: Fhb is a surface virulence protein from Streptococcus suis, which could aid bacterial evasion of host innate immune defense by recruiting complement regulator factor H to inactivate C3b deposited on bacterial surface in blood. Here we successfully expressed and purified the N terminal domain of Fhb (N-Fhb) and obtained crystals of the N-Fhb by sitting-drop vapor diffusion method with a resolution of 1.50 Å. The crystals belong to space group C2 with unit cell parameters a = 127.1 Å, b = 77.3 Å, c = 131.6 Å, α = 90°, β = 115.9°, γ = 90°. The structure of N-Fhb was determined by SAD method and the core structure of N-Fhb is a β sandwich. We speculated that binding of Fhb to human factor H may be mainly mediated by surface amino acids with negative charges.
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijng Institute of Microbiology and Infectious Disease, No. 20 Dongda Street, Fengtai District, Beijing 100071, China.
authors.forename: Chunmao
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory for Protein Sciences of Ministry of Education, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China.
authors.forename: You
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Key Laboratory for Protein Sciences of Ministry of Education, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing, China. Electronic address: maojunyang@tsinghua.edu.cn.
authors.forename: Maojun
authors.initials: M
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Pathogen and Biosecurity, Beijng Institute of Microbiology and Infectious Disease, No. 20 Dongda Street, Fengtai District, Beijing 100071, China. Electronic address: jiangyq@bmi.ac.cn.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017242:Complement Factor H / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D006801:Humans; D057131:Immune Evasion; D007113:Immunity, Innate; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055672:Static Electricity; D017011:Streptococcus suis / Q000737:chemistry* / Q000276:immunology / Q000472:pathogenicity; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D011994:Recombinant Proteins; D017242:Complement Factor H
keywords: Crystal structure; Fhb; Negative charges; Streptococcus suis; β sandwich