|
|
||||||||
Genetics and Molecular Biology |
National Institute of Agro-Environmental Sciences, Kan-nondai 3-1-1, Tsukuba, Ibaraki 305-8604, Japan1
Author for correspondence: Kiyotaka Miyashita. Tel: +81 298 388256. Fax: +81 298 388199. e-mail: kmiyas{at}s.affrc.go.jp
Streptomyces coelicolor A3(2) strain M145 has eight chitinase genes scattered on the chromosome: six genes for family 18 (chiA, B, C, D, E and H) and two for family 19 (chiF and G). In this study, the expression and regulation of these genes were investigated. The transcription of five of the genes (chiA, B, C, D and F) was induced in the presence of colloidal chitin while that of the other three genes (chiE, G and H) was not. The transcripts of the five induced chi genes increased and reached their maximum at 4 h after the addition of colloidal chitin, all showing the same temporal patterns. The induced levels of the transcripts of chiB were significantly lower than those of the other four genes. Dynamic analysis of the transcripts of the chi genes indicated that chiA and chiC were induced more strongly than chiD and chiF. Addition of chitobiose also induced transcription of the chi genes, but significantly earlier than did colloidal chitin. When cells were cultured in the presence of colloidal chitin, an exponential increase of chitobiose concentration in the culture supernatant was observed prior to the induced transcription of the chi genes. This result, together with the immediate effect of chitobiose on the induction, suggests that chitobiose produced from colloidal chitin is involved in the induction of transcription of the chi genes. The transcription of the five chi genes was repressed by glucose. This repression was apparently mediated by the glucose kinase gene glkA.
Keywords: chitin, streptomycetes, transcriptional regulation, glucose repression, chitobiose
This article has been cited by other articles:
![]() |
A. Saito, T. Shinya, K. Miyamoto, T. Yokoyama, H. Kaku, E. Minami, N. Shibuya, H. Tsujibo, Y. Nagata, A. Ando, et al. The dasABC Gene Cluster, Adjacent to dasR, Encodes a Novel ABC Transporter for the Uptake of N,N'-Diacetylchitobiose in Streptomyces coelicolor A3(2) Appl. Envir. Microbiol., May 1, 2007; 73(9): 3000 - 3008. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. C. Metcalfe, M. Krsek, G. W. Gooday, J. I. Prosser, and E. M. H. Wellington Molecular Analysis of a Bacterial Chitinolytic Community in an Upland Pasture Appl. Envir. Microbiol., October 1, 2002; 68(10): 5042 - 5050. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Saito, K. Miyashita, and H. Schrempf Characteristics of a Streptomyces coelicolor A3(2) Extracellular Protein Targeting Chitin and Chitosan Appl. Envir. Microbiol., March 1, 2001; 67(3): 1268 - 1273. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |