Crystal structure of YjeQ from Thermotoga maritima contains a circularly permuted GTPase domain.
We have determined the crystal structure of the GDP complex of the YjeQ protein from Thermotoga maritima (TmYjeQ), a member of the YjeQ GTPase subfamaily. TmYjeQ, a homologue of Escherichia coli YjeQ, which is known to bind to the ribosome, is composed of three domains: an N-terminal oligonucleotide/oligosaccharide-binding fold domain, a central GTPase domain, and a C-terminal zinc-finger domain. The crystal structure of TmYjeQ reveals two interesting domains: a circularly permutated GTPase domain and an unusual zinc-finger domain. The binding mode of GDP in the GTPase domain of TmYjeQ is similar to those of GDP or GTP analogs in ras proteins, a prototype GTPase. The N-terminal oligonucleotide/oligosaccharide-binding fold domain, together with the GTPase domain, forms the extended RNA-binding site. The C-terminal domain has an unusual zinc-finger motif composed of Cys-250, Cys-255, Cys-263, and His-257, with a remote structural similarity to a portion of a DNA-repair protein, rad51 fragment. The overall structural features of TmYjeQ make it a good candidate for an RNA-binding protein, which is consistent with the biochemical data of the YjeQ subfamily in binding to the ribosome.
Shin
Dong Hae
DH
Berkeley Structural Genomics Center, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
Lou
Yun
Y
Jancarik
Jaru
J
Yokota
Hisao
H
Kim
Rosalind
R
Kim
Sung-Hou
SH
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D020558:GTP Phosphohydrolases / Q000737:chemistry*; D008969:Molecular Sequence Data; D017510:Protein Folding; D020124:Thermotoga maritima / Q000201:enzymology*; D016335:Zinc Fingers; D018631:ras Proteins / Q000737:chemistry
D001426:Bacterial Proteins; D020558:GTP Phosphohydrolases; D018631:ras Proteins