Two heterologously expressed Planobispora rosea proteins cooperatively induce Streptomyces lividans thiostrepton uptake and storage from the extracellular medium.
BACKGROUND
A bacterial artificial chromosomal library of Planobispora rosea, a genetically intractable actinomycete strain, was constructed using Escherichia coli-Streptomyces artificial chromosome (ESAC) and screened for the presence of genes known to be involved in the biosynthesis of antibiotics.


RESULTS
One clone with a 40 kb insert showed antimicrobial activity against Gram positive bacteria. Insert sequence analysis and subcloning experiments revealed that the bioactivity was due to a 3.5 kb DNA fragment containing two open reading frames. These orfs encode two proteins with high similarity to a putative membrane protein of Streptomyces coelicolor and to the nogalamycin resistance protein SnorO of Streptomyces nogalater, respectively. The role of these two Orfs is unknown in Planobispora. Disruption and complementation experiments revealed that both proteins are necessary for the antibacterial activity and chemical analysis demonstrated that the antibiotic activity was due to thiostrepton, antibiotic used as recombinant clone selection marker.


CONCLUSIONS
Two Planobispora rosea orfs are responsible for increasing intracellular amounts and storage of thiostrepton in Streptomyces lividans.
Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Palermo, Viale delle Scienze, Ed,16, 90128 Palermo, Italy.
Anna
A
Giardina
Rosa
R
Alduina
Elvira
E
Gottardi
Valentina
V
Di Caro
Roderich D
RD
Süssmuth
Anna M
AM
Puglia
D000192:Actinomycetales / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D003001:Cloning, Molecular; D016366:Open Reading Frames; D048170:Streptomyces lividans / Q000378:metabolism*; D013883:Thiostrepton / Q000096:biosynthesis / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D013883:Thiostrepton