A regulated RNA binding protein also possesses aconitase activity.
A clone for the iron-responsive element (IRE)-binding protein (IRE-BP) has been transfected and expressed in mouse fibroblasts. The IRE-BP gene product binds IREs with high affinity and specificity. Amino acid alignments reveal that the IRE-BP is 30% identical to mitochondrial aconitase. The 18 active site residues of mitochondrial aconitase are identical to those in the IRE-BP, suggesting that the IRE-BP may possess aconitase activity. After purification of native IRE-BP and immunoaffinity purification of transfected and expressed IRE-BP, we demonstrate that the purified IRE-BP has aconitase activity.
Kaptain
S
S
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
Downey
W E
WE
Tang
C
C
Philpott
C
C
Haile
D
D
Orloff
D G
DG
Harford
J B
JB
Rouault
T A
TA
Klausner
R D
RD
D000154:Aconitate Hydratase / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D002678:Chimera; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005293:Ferritins / Q000378:metabolism; D016259:Genes, myc; D006801:Humans; D035925:Iron-Regulatory Proteins; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015183:Restriction Mapping; D014158:Transcription, Genetic; D014162:Transfection
D035925:Iron-Regulatory Proteins; D016601:RNA-Binding Proteins; D004247:DNA; D005293:Ferritins; D000154:Aconitate Hydratase