BackgroundStreptomycesare well known for their potential to produce various pharmaceutically active compounds, the commercial development of which is often limited by the low productivity and purity of the desired compounds expressed by natural producers. Well-characterized promoters are crucial for driving the expression of target genes and improving the production of metabolites of interest.ResultsA strong constitutive promoter,stnYp, was identified inStreptomyces flocculusCGMCC4.1223 and was characterized by its effective activation of silent biosynthetic genes and high efficiency of heterologous gene expression. The promoterstnYpshowed the highest activity in model strains of fourStreptomycesspecies compared with the three frequently used constitutive promotersermEp*,kasOp*, andSP44. The promoterstnYpcould efficiently activate the indigoidine biosynthetic gene cluster inS. albusJ1074, which is thought to be silent under routine laboratory conditions. Moreover,stnYpwas found suitable for heterologous gene expression in differentStreptomyceshosts. Compared with the promotersermEp*, kasOp*, andSP44,stnYpconferred the highest production level of diverse metabolites in various heterologous hosts, including the agricultural-bactericide aureonuclemycin and the antitumor compound YM-216391, with an approximately 1.4 − 11.6-fold enhancement of the yields. Furthermore, the purity of tylosin A was greatly improved by overexpressing rate-limiting genes throughstnYpin the industrial strain. Further, the yield of tylosin A was significantly elevated to 10.30 ± 0.12 g/L, approximately 1.7-fold higher than that of the original strain.ConclusionsThe promoterstnYpis a reliable, well-defined promoter with strong activity and broad suitability. The findings of this study can expand promoter diversity, facilitate genetic manipulation, and promote metabolic engineering in multipleStreptomycesspecies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12934-023-02136-9.