Phosphorylation of AfsR by multiple serine/threonine kinases in Streptomyces coelicolor A3(2).
AfsK, a protein serine/threonine kinase, autophosphorylates on serine and threonine residues and phosphorylates serine and threonine residues of AfsR, a transcriptional activator for afsS involved in secondary metabolism in Streptomyces coelicolor A3(2). pkaG encoding a 592-amino-acid protein and SCD10.09 (named afsL) encoding a 580-amino-acid protein, both of which encode an AfsK-like protein, were transcribed throughout growth. PkaG with a histidine-tag and the kinase catalytic domain of PkaG, produced in Escherichia coli, autophosphorylated dominantly on threonine and slightly on serine residues. In addition, these proteins phosphorylated AfsR on threonine and serine residues. The catalytic domain of AfsL also autophosphorylated and phosphorylated AfsR, on threonine and serine residues in both cases. AfsR was thus found to be phosphorylated by multiple kinases. Disruption of the chromosomal pkaG gene resulted in slightly reduced production of the pigmented antibiotic actinorhodin. These findings, together with the presence of about 40 AfsK homologues and at least five AfsR homologues in S. coelicolor A3(2), suggest that the regulatory networks via eukaryotic-type protein phosphorylation are more diverse and versatile than we have expected.
Sawai
Reiko
R
Department of Biotechnology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan.
Suzuki
Ayano
A
Takano
Yuji
Y
Lee
Ping-Chin
PC
Horinouchi
Sueharu
S
D000595:Amino Acid Sequence; D000880:Anthraquinones / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D000095622:Benzoisochromanequinones
D000880:Anthraquinones; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D017346:Protein Serine-Threonine Kinases; D014157:Transcription Factors; C066581:AfsR protein, Streptomyces coelicolor; C013390:actinorhodin; D000095622:Benzoisochromanequinones