Streptomyces griseus 45H, a producer of the extracellular autoregulator protein factor C, is a member of the species Streptomyces albidoflavus

Abstract

Streptomyces griseus strain 45H, isolated in 1960 during a mutagenesis programme on the industrial streptomycin producer S. griseus 52-1, encodes an extracellular, pleiotropic autoregulatory signalling protein, factor C, which stimulates sporulation of S. griseus 52-1 in submerged culture. The facC gene, which codes for factor C, is present in very few streptomycetes and is not present in S. griseus 52-1. Based on 16S rRNA gene sequencing and other molecular data, S. griseus 45H, the factor C producer, is here shown to be related to the original laboratory strain of Streptomyces flavofungini, which was being studied in the same laboratory in 1960, and to Streptomyces albidoflavus. Southern blotting revealed that three out of four independently isolated strains of S. albidoflavus possess facC. Both the original strain of S. flavofungini and S. griseus 45H are therefore identified as members of the species Streptomyces albidoflavus, and we propose that S. griseus 45H should be renamed Streptomyces albidoflavus 45H.It has been known for a long time that antibiotic production is restricted to a specific short period of the complex developmental cycle of the producer streptomycetes and that the regulation of antibiotic production is intimately interconnected with morphogenesis (Chater, 1998). This connection underlines the continuing interest in studying the morphological differentiation of many Streptomyces strains.Streptomyces griseus 45H was isolated during a mutagenesis programme aimed at the isolation of morphological mutants (non-sporulating and hypersporulating) of the industrial streptomycin producer strain Streptomyces griseus 52-1 (Szabó et al., 1960(Szabó et al., , 1961. S. griseus 45H has been described as a strain that sporulates well both on solid medium and in liquid culture, the latter being a rather rare property of Streptomyces strains. In addition, the strain secreted a substance, named factor C, into the culture medium that also induced cytodifferentiation of S. griseus 52-1 and stimulated sporulation in liquid culture.The activity of factor C was shown to be due to a protein (Biró et al., 1980). The cloning and sequencing of the facC gene (Birkó et al., 1999), which encodes this extracellular signalling protein, revealed a gene with no close relatives in the database at that time. The identity and mode of action of factor C, the morphological differentiation of S. griseus 45H and the effect of factor C on the differentiation of S. griseus 52-1 have been the subject of many publications (for a complete list see http://web.dote.hu/~sbiro/). Interaction between factor C and the regulon of S. griseus controlled by the best known c-butyrolactone autoregulator, A-factor (Ohnishi et al., 2005), has been described recently (Birkó et al., 2007).Since the two S. griseus strains (52-1 and 45H) differed in several substantial properties (Table 1), the origin of S. griseus 45H has often been questioned (Fehér & Szabó , 1978). Unquestionable evidence that the strain S. griseus 45H could not be a descendant of...

The complex extracellular biology ofStreptomyces

“…griseus 45H', a strain able to sporulate in liquid culture. This strain was recently reclassified as S. albidoflavus (Kiss et al, 2008). The effect of factor C is detectable at very low concentrations (c. 1 ng mL À1 ) (Szeszak et al, 1990).…”

“…Unusual distribution of facC‐like genes. Southern blotting and genome sequence analysis show that facC is absent from most streptomycetes, although present in two Streptomyces albus strains (Birkó et al , 1999) and most S. albidoflavus isolates (Kiss et al , 2008). This indicates that the gene may have been acquired at the time when S. albidoflavus emerged about 140 million years ago (using 1% difference in 16S rRNA gene sequence as representing approximately 50 million years' divergence: Ochman et al (1999) and A.C. Ward, pers.…”

Copper mining in Streptomyces: enzymes, natural products and development

“…Another example of a secreted substance that somehow has control over development is Factor C from S. falvofungini. 30 Factor C has been shown to be a protein of 34.5 kDa, which, when expressed in a bald, A-factor-deficient mutant of S. griseus, restores both development (aerial mycelium and spores) and A-factor production. 31…”

Mutation in <b><i>afsR</i></b> Leads to A-Factor Deficiency in <b><i>Streptomyces griseus</i></b> B2682

“…The nondifferentiating phenotype of AFN could be restored by exogenously added A-factor or by introducing the facC gene to AFN, which is responsible for the synthesis of factor C, which is an autoregulatory protein essential for the induction of differentiation in S. albidoflavus (formerly known as S. griseus 45H) [Birkó et al, 2007[Birkó et al, , 2009; Kiss et al, 2008]. These observations suggest that all the genes that function in the mode of action or in the biosynthesis of A-factor -including AfsA -are functional in AFN [Birkó et al, 2007[Birkó et al, , 2009.…”