Crystal structure of the aspartyl-tRNA synthetase from Entamoeba histolytica.
The crystal structure of the aspartyl-tRNA synthetase from the eukaryotic parasite Entamoeba histolytica has been determined at 2.8Aresolution. Relative to homologous sequences, the E. histolytica protein contains a 43-residue insertion between the N-terminal anticodon binding domain and the C-terminal catalytic domain. The present structure reveals that this insertion extends an arm of the hinge region that has previously been shown to mediate interaction of aspartyl-tRNA synthetase with the cognate tRNA D-stem. Modeling indicates that this Entamoeba-specific insertion is likely to increase the interaction surface with the cognate tRNA(Asp). In doing so it may substitute functionally for an RNA-binding motif located in N-terminal extensions found in AspRS sequences from lower eukaryotes but absent in Entamoeba. The E. histolytica AspRS structure shows a well-ordered N-terminus that contributes to the AspRS dimer interface.
Merritt
Ethan A
EA
Department of Biochemistry, University of Washington, Mailstop 357742, Seattle, WA 98195, USA. merritt@u.washington.edu
Arakaki
Tracy L
TL
Larson
Eric T
ET
Kelley
Angela
A
Mueller
Natascha
N
Napuli
Alberto J
AJ
Zhang
Li
L
Deditta
George
G
Luft
Joseph
J
Verlinde
Christophe L M J
CL
Fan
Erkang
E
Zucker
Frank
F
Buckner
Frederick S
FS
Van Voorhis
Wesley C
WC
Hol
Wim G J
WG
D000595:Amino Acid Sequence; D000818:Animals; D001226:Aspartate-tRNA Ligase / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D004748:Entamoeba histolytica / Q000737:chemistry* / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry*; D016415:Sequence Alignment
D015800:Protozoan Proteins; D001226:Aspartate-tRNA Ligase