Structures of the rat proteasomal ATPases: determination of highly conserved structural motifs and rules for their spacing.
We have isolated rat cDNAs for all of the five known proteasomal ATPases. The protein sequences of rat TBP1, TBP7, MSS1, S4, and SUG1 predicted from the open reading frames consist of 439, 418, 433, 440, and 406 amino acid residues, respectively, and exhibit striking similarities to each human counterpart with only several amino acid substitutions. These five rat ATPases are also highly homologous with each other. The N-terminal region in rat TBP1, TBP7, and SUG1 contains a heptad repeat of hydrophobic amino acids reminiscent of a leucine zipper. Also, in the central region of each rat ATPase, we found four conserved motifs, Gx4GKT, DEID, SAT, and H/QRxGRx2R, that are characteristic of a large family of ATP-dependent RNA/DNA helicases. The spacing between individual motifs was strictly conserved in the rat ATPases. These findings suggest a common function of the rat proteasomal ATPases in ATP-dependent RNA/DNA unwinding.
Makino
Y
Y
Department of Biology, Faculty of Science, Chiba University, Japan.
Yogosawa
S
S
Kanemaki
M
M
Yoshida
T
T
Yamano
K
K
Kishimoto
T
T
Moncollin
V
V
Egly
J M
JM
Muramatsu
M
M
Tamura
T
T
D000074183:ATPases Associated with Diverse Cellular Activities; D000251:Adenosine Triphosphatases / Q000096:biosynthesis / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003546:Cysteine Endopeptidases / Q000096:biosynthesis / Q000737:chemistry*; D004265:DNA Helicases / Q000737:chemistry; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000737:chemistry; D006801:Humans; D008099:Liver / Q000201:enzymology; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000737:chemistry*; D016366:Open Reading Frames; D010446:Peptide Fragments / Q000737:chemistry; D046988:Proteasome Endopeptidase Complex; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009097:Multienzyme Complexes; D010446:Peptide Fragments; D011994:Recombinant Proteins; D014157:Transcription Factors; D003546:Cysteine Endopeptidases; C088863:PSMC4 protein, human; D046988:Proteasome Endopeptidase Complex; D000251:Adenosine Triphosphatases; D000074183:ATPases Associated with Diverse Cellular Activities; D004265:DNA Helicases; C484220:Psmc4 protein, rat