title: Crystal structure of NusG N-terminal (NGN) domain from Methanocaldococcus jannaschii and its interaction with rpoE''.
abstract: Transcription in archaea employs a eukaryotic-type transcription apparatus but uses bacterial-type transcription factors. NusG is one of the few archaeal transcription factors whose orthologs are essential in both bacteria and eukaryotes. Archaeal NusG is composed of only an NusG N-terminal (NGN) domain and a KOW domain, which is similar to bacterial NusG but not to the eukaryotic ortholog, Spt5. However, archaeal NusG was confirmed recently to form a complex with rpoE'' that was similar to the Spt5-Spt4 complex. Thus, archaeal NusG presents hybrid features of Spt5 and bacterial NusG. Here we report the crystal structure of NGN from the archaea Methanocaldococcus jannaschii (MjNGN). MjNGN folds to an alpha-beta-alpha sandwich without the appendant domain of bacterial NGNs, and forms a unique homodimer in crystal and solution. MjNGN alone was found to be sufficient for rpoE'' binding and an MjNGN-rpoE'' model has been constructed by rigid docking.
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: Huihao
authors.initials: H
authors.lastname: Zhou
authors.forename: Qi
authors.initials: Q
authors.lastname: Liu
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Gao
authors.forename: Maikun
authors.initials: M
authors.lastname: Teng
authors.forename: Liwen
authors.initials: L
authors.lastname: Niu
mesh_terms: D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D018360:Crystallography, X-Ray; D017016:Methanococcaceae / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry*
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D014157:Transcription Factors