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 2003/03
形態種別 研究論文
査読 査読あり
標題 The first crystal structure of archaeal aldolase - Unique tetrameric structure of 2-deoxy-D-ribose-5-phosphate aldolase from the hyperthermophilic archaea Aeropyrum pernix
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 278(12),pp.10799-10806
著者・共著者 H Sakuraba,H Tsuge,Shimoya, I,R Kawakami,S Goda,Y Kawarabayasi,N Katunuma,H Ago,M Miyano,T Ohshima
概要 A gene encoding a 2-deoxy-D-ribose-5-phosphate aldolase (DERA) homolog was identified in the hyperthermophilic Archaea Aeropyrum pernix. The gene was over-expressed in Escherichia coli, and the produced enzyme was purified and characterized. The enzyme is an extremely thermostable DERA, its activity was not lost after incubation at 100 degreesC for 10 min. The enzyme has a molecular mass of similar to93 kDa and consists of four subunits with an identical molecular mass of 24 kDa. This is the first report of the presence of tetrameric DERA. The three-dimensional structure of the enzyme was determined by x-ray analysis. The subunit folds into an alpha/beta-barrel. The asymmetric unit consists of two homologous subunits, and a crystallographic 2-fold axis generates the functional tetramer. The main chain coordinate of the monomer of the A. pernix enzyme is quite similar to that of the E. coli enzyme. There was no significant difference in hydrophobic interactions and the number of ion pairs between the monomeric structures of the two enzymes. However, a significant difference in the quaternary structure was observed. The area of the subunit-subunit interface in the dimer of the A. pernix enzyme is much larger compared with the E. coli enzyme. In addition, the A. pernix enzyme is 10 amino acids longer than the E. coli enzyme in the N-terminal region and has an additional N-terminal helix. The N-terminal helix produces a unique dimer-dimer interface. This promotes the formation of a functional tetramer of the A. pernix enzyme and strengthens the hydrophobic inter-subunit interactions. These structural features are considered to be responsible for the extremely high stability of the A. pernix enzyme. This is the first description of the structure of hyperthermophilic DERA and of aldolase from the Archaea domain.
DOI 10.1074/jbc.M212449200
ISSN 0021-9258