Regulation of cellulase synthesis in Thermomonospora fusca and cloning, sequencing and expression of an alkaline serine protease gene in Thermomonospora fusca.

摘要

Thermomonospora fusca is a thermophilic, filamentous Gram positive soil bacterium The regulation of T. fusca cellulase synthesis has been shown to involve dual control by both induction and repression Two cloned cellulose genes from Streptomyces also contain the same 14 base pair sequence. Extracts from S. lividans grown on cellobiose but not on glucose contain a factor that binds to this regulatory sequence, suggesting that the induction of cellulase genes may be conserved among different acetomycete organisms.As part of my thesis, I initiated a second project where I cloned, sequenced and expressed an alkaline serine protease gene from T. fusca. A 2.7 kb Kpn I-Pst I fragment containing a complete protease gene from T. fusca chromosomal DNA was cloned into Escherichia coli in plasmid pUC19 and subcloned into shuttle vector pSES 1. The protease gene was expressed in S. lividans, but not in E. coli. Analysis of the protein sequence deduced from the nucleotide sequence indicates that the T. fusca protease-TFP1 is synthesized as a prepro protein, which is subsequently processed to its mature extracellular form (19kDa). The T. fusca mature protease was contained within the C-terminal end of the precursor Tfp 1. The mature protease amino acid sequence showed 47% identity with the Lysobacter enzmogenes