Abstract
The nucleotide sequence of a 1860-bp region encoding a thermostable α-amylase of Streptomyces sp. TO1 was determined. Frame analysis revealed the presence of a 1359-bp long open reading frame ( amy TO1) encoding a 453 amino acid protein with a deduced M r of 49 kDa. Northern blot analysis revealed that amy TO1 gene was expressed as approximately 1.5-kbp monocistronic transcript in both SL1326/pLM1 and Streptomyces sp. TO1 strains. Primer extension experiments indicated that the transcriptional start site lies 30 bp upstream of the ATG start codon, and allowed the identification of −35 (TTGCTG) and −10 (TACGCG) eubacterial-like promoter sequences. Amy TO1 exhibits strong amino acid identities with those from other Streptomyces species with a maximum of 78% with S. thermoviolaceus α-amylase. Nevertheless, subtle amino acid changes such as the substitution of four conserved residues found at similar positions in other Streptomyces α-amylases by proline residues, and the substitution of three conserved hydrophilic amino acids by hydrophobic ones in Amy TO1 might account for the thermostable properties of Amy TO1.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
