This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Zhu, D. Articles by Deng, Z. Search for Related Content PubMed PubMed Citation Articles by Zhu, D. Articles by Deng, Z.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2005, p. 3180-3187, Vol. 187, No. 9
0021-9193/05/$08.00+0     doi:10.1128/JB.187.9.3180-3187.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Expression of the melC Operon in Several Streptomyces Strains Is Positively Regulated by AdpA, an AraC Family Transcriptional Regulator Involved in Morphological Development in Streptomyces coelicolor

Dongqing Zhu, Xinyi He, Xiufen Zhou, and Zixin Deng^*

Bio-X Life Science Research Centre and School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai, People's Republic of China

Received 13 October 2004/ Accepted 3 January 2005

Dark brown haloes of melanin around colonies are an easily visualized phenotype displayed by many Streptomyces strains harboring plasmid pIJ702 carrying the melC operon of Streptomyces antibioticus IMRU3270. Spontaneous melanin-negative mutants of pIJ702 occur with a frequency of ca. 1%, and often mutation occurs in the melC operon, which removes the BglII site as part of an inverted repeat. Other melanin-negative mutations seem to occur spontaneously in Streptomyces lividans, resulting in white colonies from which intact, melanin-producing pIJ702 can be isolated by introduction into a new host. S. lividans ZX66 was found to be such a mutant and to have a secondary mutation influencing expression of the melC operon on the chromosome. A 3.3-kb DNA fragment was isolated from its progenitor strain, JT46, and a gene able to restore melC operon expression was found to encode a member of an AraC family of transcriptional regulators, which was equivalent to AdpA_c in Streptomyces coelicolor and therefore was designated AdpA_l. Lack of melC operon expression was correlated with a single A-to-C transversion, which altered a single key amino acid residue from Thr to Pro. The transcription of the melC operon was found to be greatly reduced in the adpA mutant background. The counterpart gene (adpA_a) in the S. antibioticus strain in which the melC operon carried on pIJ702 originated was also isolated and was found to have an identical regulatory role. Thus, we concluded that the melC operon is under general direct positive control by AdpA family proteins, perhaps at the transcriptional level and certainly at the translational level via bldA, in Streptomyces.

---

* Corresponding author. Mailing address: Bio-X Life Science Research Center, Shanghai Jiaotong University, Shanghai 200030, People's Republic of China. Phone: 86 21 62933404. Fax: 86 21 62932418. E-mail: zxdeng{at}sjtu.edu.cn.

---

Journal of Bacteriology, May 2005, p. 3180-3187, Vol. 187, No. 9
0021-9193/05/$08.00+0     doi:10.1128/JB.187.9.3180-3187.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• van Wezel, G. P., Krabben, P., Traag, B. A., Keijser, B. J. F., Kerste, R., Vijgenboom, E., Heijnen, J. J., Kraal, B. (2006). Unlocking Streptomyces spp. for Use as Sustainable Industrial Production Platforms by Morphological Engineering. Appl. Environ. Microbiol. 72: 5283-5288 [Abstract] [Full Text]