AUTHOR=Ramzan Rabia , Virk Muhammad Safiullah , Chen Fusheng 

TITLE=The ABCT31 Transporter Regulates the Export System of Phenylacetic Acid as a Side-Chain Precursor of Penicillin G in Monascus ruber M7

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.915721

DOI=10.3389/fmicb.2022.915721

ISSN=1664-302X

ABSTRACT=<p>The biosynthesis of penicillin G (PG) is compartmentalized, and the transportation of the end and intermediate products, and substrates (precursors) such as L-cysteine (L-Cys), L-valine (L-Val) and phenylacetic acid (PAA) requires traversing membrane barriers. However, the transportation system of PAA as a side chain of PG are unclear yet. To discover ABC transporters (ABCTs) involved in the transportation of PAA, the expression levels of 38 ABCT genes in the genome of <italic>Monascus ruber</italic> M7, culturing with and without PAA, were examined, and found that one <italic>abct</italic> gene, namely <italic>abct</italic>31, was considerably up-regulated with PAA, indicating that <italic>abct</italic>31 may be relative with PAA transportation. Furthermore the disruption of <italic>abct</italic>31 was carried out, and the effects of two PG substrate's amino acids (L-Cys and L-Val), PAA and some other weak acids on the morphologies and production of secondary metabolites (SMs) of Δ<italic>abct</italic>31 and <italic>M. ruber</italic> M7, were performed through feeding experiments. The results revealed that L-Cys, L-Val and PAA substantially impacted the morphologies and SMs production of Δ<italic>abct</italic>31 and <italic>M. ruber</italic> M7. The UPLC-MS/MS analysis findings demonstrated that Δ<italic>abct</italic>31 did not interrupt the synthesis of PG in <italic>M. ruber</italic> M7. According to the results, it suggests that <italic>abct</italic>31 is involved in the resistance and detoxification of the weak acids, including the PAA in <italic>M. ruber</italic> M7.</p>