Detection and properties of A-factor-binding protein from Streptomyces griseus.
The optically active form of tritium-labeled A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone), a pleiotropic autoregulator responsible for streptomycin production, streptomycin resistance, and sporulation in Streptomyces griseus, was chemically synthesized. By using the radioactive A-factor, a binding protein for A-factor was detected in the cytoplasmic fraction of this organism. The binding protein had an apparent molecular weight of approximately 26,000, as determined by gel filtration. Scatchard analysis suggested that A-factor bound the protein in the molar ratio of 1:1 with a binding constant, Kd, of 0.7 nM. The number of the binding protein was roughly estimated to be 37 per genome. The "inducing material" virginiae butanolide C (VB-C), which has a structure very similar to that of A-factor and is essential for virginiamycin production in Streptomyces virginiae, did not inhibit binding. In addition, no protein capable of specifically binding 3H-labeled VB-C was found in S. griseus. Together with the observation that VB-C had almost no biological activity on the restoration of streptomycin production or sporulation in an A-factor-deficient mutant of S. griseus, these results indicated that the binding protein had a strict ligand specificity. Examination for an A-factor-binding protein in Streptomyces coelicolor A3(2) and Streptomyces lividans showed the absence of any specifically binding protein.
Miyake
K
K
Department of Agricultural Chemistry, University of Tokyo, Japan.
Horinouchi
S
S
Yoshida
M
M
Chiba
N
N
Mori
K
K
Nogawa
N
N
Morikawa
N
N
Beppu
T
T
D015107:4-Butyrolactone / Q000031:analogs & derivatives; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006133:Growth Substances / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D013305:Streptomyces griseus / Q000254:growth & development / Q000378:metabolism*; D014316:Tritium
D002352:Carrier Proteins; D006133:Growth Substances; D014316:Tritium; C025035:A-factor (Streptomyces); D015107:4-Butyrolactone