title: Solution structure of tandem SH2 domains from Spt6 protein and their binding to the phosphorylated RNA polymerase II C-terminal domain.
abstract: Spt6 is a highly conserved transcription elongation factor and histone chaperone. It binds directly to the RNA polymerase II C-terminal domain (RNAPII CTD) through its C-terminal region that recognizes RNAPII CTD phosphorylation. In this study, we determined the solution structure of the C-terminal region of Saccharomyces cerevisiae Spt6, and we discovered that Spt6 has two SH2 domains in tandem. Structural and phylogenetic analysis revealed that the second SH2 domain was evolutionarily distant from canonical SH2 domains and represented a novel SH2 subfamily with a novel binding site for phosphoserine. In addition, NMR chemical shift perturbation experiments demonstrated that the tandem SH2 domains recognized Tyr(1), Ser(2), Ser(5), and Ser(7) phosphorylation of RNAPII CTD with millimolar binding affinities. The structural basis for the binding of the tandem SH2 domains to different forms of phosphorylated RNAPII CTD and its physiological relevance are discussed. Our results also suggest that Spt6 may use the tandem SH2 domain module to sense the phosphorylation level of RNAPII CTD.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Jiahai
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Qingguo
authors.initials: Q
authors.lastname: Gong
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xiong
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Hongda
authors.initials: H
authors.lastname: Huang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Lu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China. Electronic address: wujihui@ustc.edu.cn.
authors.forename: Jihui
authors.initials: J
authors.lastname: Wu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China. Electronic address: yyshi@ustc.edu.cn.
authors.forename: Yunyu
authors.initials: Y
authors.lastname: Shi
mesh_terms: D001665:Binding Sites / Q000502:physiology; D019143:Evolution, Molecular; D056488:Histone Chaperones; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D010802:Phylogeny; D011485:Protein Binding; D012319:RNA Polymerase II / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D035602:Transcriptional Elongation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018909:src Homology Domains
chemical_list: D056488:Histone Chaperones; D009687:Nuclear Proteins; C065456:SPT6 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D035602:Transcriptional Elongation Factors; D012319:RNA Polymerase II