Yeast genetic codes - Endogenous Stochastic Decoding of the CUG Codon by Competing Ser- and Leu-tRNAs in Ascoidea asiatica

ABSTRACT: While the “universal” genetic code is now known not to be universal, and stop codons can have multiple meanings, one regularity remains, namely that for a given sense codon there is a unique translation. Examining CUG usage in yeasts that have transferred CUG away from leucine, we here report the first example of dual coding: Ascoidea asiatica stochastically encodes CUG as both serine and leucine. This is deleterious as evidenced by CUG codons being rare, never at conserved serine/leucine residues and predominantly in lowly expressed genes. Related yeasts solve the problem by loss-of-function of one of the two tRNAs. This dual-coding is consistent with the tRNA-loss driven codon reassignment hypothesis and provides a unique example of a proteome that cannot be deterministically predicted.

INSTRUMENT(S):

ORGANISM(S): Saccharomycopsis Malanga Ascoidea Asiatica Nakazawaea Peltata Ascoidea Rubescens Dsm 1968 Clavispora Lusitaniae Atcc 42720 Saccharomycopsis Fibuligera Babjeviella Inositovora Nrrl Y-12698

TISSUE(S): Vegetative Cell (sensu Fungi)

SUBMITTER: Martin Kollmar  

LAB HEAD: Martin Kollmar

PROVIDER: PXD009494 | Pride | 2018-06-13

REPOSITORIES: Pride