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Updated: Jun 12, 2026
Identifying Amino Acid Overproducers Using Rare-Codon-Rich Markers
Published on: June 24, 2019
Use of the pyrG gene as a food-grade selection marker in Monascus
Bo-hua Wang1, Yang Xu, Yan-ping Li
1State Key Laboratory of Food Science and Technology, Nanchang University, Nanjing East Road 235, Nanchang, Jiangxi 330047, China.
Abstract:
Ma-pyrG was cloned from Monascus aurantiacus AS3.4384 using degenerate PCR with primers designed with an algorithm called CODEHOP, and its complete sequence was obtained by a PCR-based strategy for screening a Monascus fosmid library. Ma-pyrG encodes orotidine-5'-phosphate decarboxylase (OMPdecase), a 283-aminoacid protein with 81% sequence identity to that from Aspergillus flavus NRRL 3357. A pyrG mutant strain from M. aurantiacus AS3.4384, named UM28, was isolated by resistance to 5-fluoroorotic acid after UV mutagenesis. Sequence analysis of this mutated gene revealed that it contained a point mutation at nucleotide position +220. Plasmid pGFP-pyrG, bearing the green fluorescent protein gene (GFP) as a model gene and Ma-pyrG as a selection marker, were constructed. pGFP-pyrG were successfully transformed into UM28 by using the PEG method.
