Cloning and sequence analysis of the human mitochondrial translational initiation factor 2 cDNA.
Complete cDNAs encoding human mitochondrial translational initiation factor 2 (IF-2mt) have been obtained from liver, heart, and fetal brain cDNA libraries. These cDNAs have a long open reading frame 2181 residues in length encoding a protein of 727 amino acids. Overall, human IF-2mt has 30-40% identity to the corresponding prokaryotic factors. Surprisingly, it is no more homologous to yeast IF-2mt than to the IF-2s from bacterial sources. The greatest region of conservation lies in the G-domain of this factor with less conservation in the COOH-terminal half of the protein and very little homology near the amino terminus. The 5'-untranslated leaders of the liver and heart cDNAs contain a number of short open reading frames. These sequences may play a role in the translational activity of the IF-2mt mRNA. Northern analysis indicates that the IF-2mt gene is expressed in all tissues but that the level of expression varies over a wide range.
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Department of Chemistry, University of North Carolina, Chapel Hill 27599.
Spremulli
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D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000096:biosynthesis / Q000737:chemistry; D005333:Fetus; D015723:Gene Library; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism; D016366:Open Reading Frames; D010448:Peptide Initiation Factors / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D016133:Polymerase Chain Reaction; D039881:Prokaryotic Initiation Factor-2; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018076:DNA, Complementary; D010448:Peptide Initiation Factors; D039881:Prokaryotic Initiation Factor-2