title: Identification of RNAIII-binding proteins in Staphylococcus aureus using tethered RNAs and streptavidin aptamers based pull-down assay.
abstract: BACKGROUND
  It has been widely recognized that small RNAs (sRNAs) play important roles in physiology and virulence control in bacteria. In Staphylococcus aureus, many sRNAs have been identified and some of them have been functionally studied. Since it is difficult to identify RNA-binding proteins (RBPs), very little has been known about the RBPs in S. aureus, especially those associated with sRNAs.
  
  
  RESULTS
  Here we adopted a tRNA scaffold streptavidin aptamer based pull-down assay to identify RBPs in S. aureus. The tethered RNA was successfully captured by the streptavidin magnetic beads, and proteins binding to RNAIII were isolated and analyzed by mass spectrometry. We have identified 81 proteins, and expressed heterologously 9 of them in Escherichia coli. The binding ability of the recombinant proteins with RNAIII was further analyzed by electrophoresis mobility shift assay, and the result indicates that proteins CshA, RNase J2, Era, Hu, WalR, Pyk, and FtsZ can bind to RNAIII.
  
  
  CONCLUSIONS
  This study suggests that some proteins can bind to RNA III in S. aureus, and may be involved in RNA III function. And tRSA based pull-down assay is an effective method to search for RBPs in bacteria, which should facilitate the identification and functional study of RBPs in diverse bacterial species.
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. zhangxut@mail.ustc.edu.cn.
authors.forename: Xu
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. zhuqq@mail.ustc.edu.cn.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. tian8687@mail.ustc.edu.cn.
authors.forename: Tian
authors.initials: T
authors.lastname: Tian
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. clzhao@mail.ustc.edu.cn.
authors.forename: Changlong
authors.initials: C
authors.lastname: Zhao
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. zangjy@ustc.edu.cn.
authors.forename: Jianye
authors.initials: J
authors.lastname: Zang
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. xuet@ahau.edu.cn.|School of Life Sciences, Anhui Agricultural University, Hefei, Anhui, 230036, China. xuet@ahau.edu.cn.
authors.forename: Ting
authors.initials: T
authors.lastname: Xue
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230027, China. sunb@ustc.edu.cn.|CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui, 230027, China. sunb@ustc.edu.cn.
authors.forename: Baolin
authors.initials: B
authors.lastname: Sun
mesh_terms: D040901:Proteomics / Q000379:methods; D012329:RNA, Bacterial / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry; D016601:RNA-Binding Proteins / Q000032:analysis*; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000502:physiology; D019809:Streptavidin / Q000737:chemistry
chemical_list: D012329:RNA, Bacterial; D016601:RNA-Binding Proteins; C096035:RNAIII, Staphylococcus aureus; D019809:Streptavidin; D012343:RNA, Transfer