ツゲ ヒデアキ   TSUGE HIDEAKI
  津下 英明
   所属   京都産業大学  生命科学部 先端生命科学科
   職種   教授
言語種別 英語
発行・発表の年月 2009/03
形態種別 研究論文
査読 査読あり
標題 Structural Basis of the Influenza A Virus RNA Polymerase PB2 RNA-binding Domain Containing the Pathogenicity-determinant Lysine 627 Residue
執筆形態 その他
掲載誌名 JOURNAL OF BIOLOGICAL CHEMISTRY
出版社・発行元 AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
巻・号・頁 284(11),pp.6855-6860
担当区分 最終著者
著者・共著者 Takashi Kuzuhara,Daisuke Kise,Hiroko Yoshida,Takahiro Horita,Yoshimi Murazaki,Akie Nishimura,Noriko Echigo,Hiroko Utsunomiya,Hideaki Tsuge
概要 Because the influenza A virus has an RNA genome, its RNA-dependent RNA polymerase, comprising the PA, PB1, and PB2 subunits, is essential for viral transcription and replication. The binding of RNAprimers/promoters to the polymerases is an initiation step in viral transcription. In our current study, we reveal the 2.7 A tertiary structure of the C-terminal RNA-binding domain of PB2 by x-ray crystallography. This domain incorporates lysine 627 of PB2, and this residue is associated with the high pathogenicity and host range restriction of influenza A virus. We found from our current analyses that this lysine is located in a unique "phi"-shaped structure consisting of a helix and an encircled loop within the PB2 domain. By electrostatic analysis, we identified a highly basic groove along with this phi loop and found that lysine 627 is located in the phi loop. A PB2 domain mutant in which glutamic acid is substituted at position 627 shows significantly lower RNA binding activity. This is the first report to show a relationship between RNA binding activity and the pathogenicity-determinant lysine 627. Using the Matras program for protein three-dimensional structural comparisons, we further found that the helix bundles in the PB2 domain are similar to that of activator 1, the 40-kDa subunit of DNA replication clamp loader (replication factor C), which is also an RNA-binding protein. This suggests a functional and structural relationship between the RNA-binding mechanisms underlying both influenza A viral transcription and cellular DNA replication. Our present results thus provide important new information for developing novel drugs that target the primer/promoter RNA binding of viral RNA polymerases.
DOI 10.1074/jbc.C800224200
ISSN 0021-9258/1083-351X