A. Arisawa et al., CLONING AND NUCLEOTIDE-SEQUENCES OF 2 GENES INVOLVED IN THE 4''-O-ACYLATION OF MACROLIDE ANTIBIOTICS FROM STREPTOMYCES-THERMOTOLERANS, Bioscience, biotechnology, and biochemistry, 57(12), 1993, pp. 2020-2025
A DNA fragment responsible for the 4''-O-acylation of macrolide antibi
otics was cloned from a mutant strain of the carbomycin producer Strep
tomyces thermotolerans. The gene encoding the macrolide 4''-O-acyltran
sferase was within a 2.7-kb region of the cloned fragment (15-kb). Str
eptomyces lividans carrying the region converted exogenously added tyl
osin to 4''-O-acyltylosins. Nucleotide sequencing of the region showed
two open reading frames (ORFs). Expression assay using deleted plasmi
ds showed that both ORFs were essential for optimal expression of the
acyltransferase activity. One of them (acyB1) was identical with care
reported previously as a gene encoding 4''-mycarosyl isovaleryl-CoA tr
ansferase. The other (acyB2) was assumed to encode a novel regulatory
protein that could activate acyB1 expression. acyB1 and acyB2 were hig
hly conserved among streptomycetes with macrolide 4''-O-acyl transfera
se activity.