Protozyme: emerging evidence in nature.
The VMA1 locus in Saccharomyces cerevisiae contains a nested genetic element, the VDE gene, and expresses two functional proteins. A single VMA1 translational product seems to catalyze a self protein splicing in which an internal domain is excised out to produce a site-specific DNA endonuclease and the N- and C-domains are ligated by a transpeptidation reaction to yield a catalytic subunit of the vacuolar ATPase. Accumulating evidence in the past few years suggests that the VMA1 locus encodes a protozyme (for protos en zyme) which has dual roles in life as a protean catalyst for self protein splicing and for self gene homing. Four protozymes that share a common mechanism in protein splicing have been found in four organisms covering three major phylogenic trees.
Anraku
Y
Y
Department of Plant Sciences, Graduate School of Science, University of Tokyo.
Hirata
R
R
D000595:Amino Acid Sequence; D004706:Endodeoxyribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000235:genetics; D005800:Genes, Fungal; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D014176:Protein Biosynthesis; D006180:Proton-Translocating ATPases; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins
D029701:Saccharomyces cerevisiae Proteins; D004706:Endodeoxyribonucleases; D006180:Proton-Translocating ATPases; C081687:VMA1 protein, S cerevisiae