Crystal structure of a predicted phosphoribosyltransferase (TT1426) from Thermus thermophilus HB8 at 2.01 A resolution.
TT1426, from Thermus thermophilus HB8, is a conserved hypothetical protein with a predicted phosphoribosyltransferase (PRTase) domain, as revealed by a Pfam database search. The 2.01 A crystal structure of TT1426 has been determined by the multiwavelength anomalous dispersion (MAD) method. TT1426 comprises a core domain consisting of a central five-stranded beta sheet surrounded by four alpha-helices, and a subdomain in the C terminus. The core domain structure resembles those of the type I PRTase family proteins, although a significant structural difference exists in an inserted 43-residue region. The C-terminal subdomain corresponds to the "hood," which contains a substrate-binding site in the type I PRTases. The hood structure of TT1426 differs from those of the other type I PRTases, suggesting the possibility that TT1426 binds an unknown substrate. The structure-based sequence alignment provides clues about the amino acid residues involved in catalysis and substrate binding.
Kukimoto-Niino
Mutsuko
M
RIKEN Genomic Sciences Center, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan.
Shibata
Rie
R
Murayama
Kazutaka
K
Hamana
Hiroaki
H
Nishimoto
Madoka
M
Bessho
Yoshitaka
Y
Terada
Takaho
T
Shirouzu
Mikako
M
Kuramitsu
Seiki
S
Yokoyama
Shigeyuki
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D010430:Pentosyltransferases / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016963:Thermus thermophilus / Q000201:enzymology* / Q000235:genetics
D001426:Bacterial Proteins; D010430:Pentosyltransferases; C023269:uracil phosphoribosyltransferase