title: Crystal Structure of Human SSRP1 Middle Domain Reveals a Role in DNA Binding.
abstract: SSRP1 is a subunit of the FACT complex, an important histone chaperone required for transcriptional regulation, DNA replication and damage repair. SSRP1 also plays important roles in transcriptional regulation independent of Spt16 and interacts with other proteins. Here, we report the crystal structure of the middle domain of SSRP1. It consists of tandem pleckstrin homology (PH) domains. These domains differ from the typical PH domain in that PH1 domain has an extra conserved βαβ topology. SSRP1 contains the well-characterized DNA-binding HMG-1 domain. Our studies revealed that SSRP1-M can also participate in DNA binding, and that this binding involves one positively charged patch on the surface of the structure. In addition, SSRP1-M did not bind to histones, which was assessed through pull-down assays. This aspect makes the protein different from other related proteins adopting the double PH domain structure. Our studies facilitate the understanding of SSRP1 and provide insights into the molecular mechanisms of interaction with DNA and histones of the FACT complex.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Fuxing
authors.initials: F
authors.lastname: Zeng
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Chen
authors.initials: C
authors.lastname: Shao
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Sai
authors.initials: S
authors.lastname: Li
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Lv
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Yunyu
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Liwen
authors.initials: L
authors.lastname: Niu
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Maikun
authors.initials: M
authors.lastname: Teng
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, Innovation Center for Cell Signaling Network, School of Life Science, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.|Key Laboratory of Structural Biology, Hefei Science Center of CAS, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui, 230026, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Li
mesh_terms: D018797:Cell Cycle Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006609:High Mobility Group Proteins / Q000737:chemistry* / Q000378:metabolism; D006657:Histones / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D011487:Protein Conformation; D000072417:Protein Domains; D014157:Transcription Factors / Q000737:chemistry; D035602:Transcriptional Elongation Factors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D006657:Histones; C073537:SSRP1 protein, human; C489489:SUPT16H protein, human; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D004247:DNA