The structure of the flexible arm of Thermotoga maritima tRNase Z differs from those of homologous enzymes.
tRNA 3'-processing endoribonuclease (tRNase Z) is one of the enzymes involved in the 3'-end processing of precursor tRNAs and is a member of the metallo-beta-lactamase superfamily. tRNase Z crystal structures have revealed that the enzyme forms a dimer and has a characteristic domain, named a flexible arm or an exosite, which protrudes from the metallo-beta-lactamase core and is involved in tRNA binding. The refined structure of Thermotoga maritima tRNase Z has been determined at 1.97 A resolution, revealing the structure of the flexible arm and the zinc-bound active site. The structure of the flexible arm of T. maritima tRNase Z is distinct from those of the Bacillus subtilis and Escherichia coli tRNase Zs. A comparison of the three tRNase Z structures revealed differences in the dimer orientation, which may be related to the unique cleavage-site specificity of T. maritima tRNase Z.
Ishii
Ryohei
R
RIKEN Genomic Sciences Center, Tsurumi, Yokohama 230-0045, Japan.
Minagawa
Asako
A
Takaku
Hiroaki
H
Takagi
Masamichi
M
Nashimoto
Masayuki
M
Yokoyama
Shigeyuki
S
D000595:Amino Acid Sequence / Q000502:physiology; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004722:Endoribonucleases / Q000737:chemistry*; D008969:Molecular Sequence Data; D017510:Protein Folding; D040681:Structural Homology, Protein; D020124:Thermotoga maritima / Q000201:enzymology*
D004722:Endoribonucleases; C110250:RNase Z