Purification and characterization of an RNA dodecamer sequence binding protein from mitochondria of Saccharomyces cerevisiae.
Saccharomyces cerevisiae mitochondrial mRNAs terminate at their 3' ends with a conserved dodecamer sequence, 5'-AAUAA(U/C)AUUCUU-3'. We have identified a nuclear-encoded protein (DBP) which specifically binds to the dodecamer sequence and have purified it to apparent homogeneity by RNA affinity chromatography. DBP consists of a single polypeptide of 55 kDa and binds to its RNA substrate with a 1:1 stoichiometry. Scatchard analysis determines that K(d) is 0.93 nM for the canonical dodecamer sequence (5'-AAUAAUAUUCUU-3') and 0.46 nM for the only naturally occurring variant (5'-AAUAACAUUCUU-3') unique to oli1 gene. Based on the studies using mutant oligonucleotides, DBP appears to recognize primarily the nucleotide sequence of an RNA rather than its potential secondary structure.
Li
H
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Department of Molecular Microbiology and Immunology, St. Louis University Health Sciences Center, St. Louis, Missouri, 63104, USA.
Zassenhaus
H P
HP
D001483:Base Sequence; D001665:Binding Sites; D008928:Mitochondria / Q000737:chemistry*; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry / Q000378:metabolism; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure*
D009841:Oligonucleotides; D016601:RNA-Binding Proteins; D012313:RNA