Lantibiotics are ribosomally synthesized oligopeptide antibiotics that contain lanthionine bridges derived by the posttranslational modification of amino acid residues. Here, we describe the cinnamycin biosynthetic gene cluster (cin) from Streptomyces cinnamoneus cinnamoneus DSM 40005, the first, to our knowledge, lantibiotic gene cluster from a high G؉C bacterium to be cloned and sequenced. The cin cluster contains many genes not found in lantibiotic clusters from low G؉C Gram-positive bacteria, including a Streptomyces antibiotic regulatory protein regulatory gene, and lacks others found in such clusters, such as a LanT-type transporter and a LanP-type protease. Transfer of the cin cluster to Streptomyces lividans resulted in heterologous production of cinnamycin. Furthermore, modification of the cinnamycin structural gene (cinA) led to production of two naturally occurring lantibiotics, duramycin and duramycin B, closely resembling cinnamycin, whereas attempts to make a more widely diverged derivative, duramycin C, failed to generate biologically active material. These results provide a basis for future attempts to construct extensive libraries of cinnamycin variants.C innamycin (Fig. 1) is a peptide antibiotic produced by several Streptomyces strains, including Streptomyces cinnamoneus cinnamoneus DSM 40005. It is assumed to be made by posttranslational modification and processing of a larger ribosomally synthesized peptide. Modifications include the formation of lanthionine bridges, which are thio-ether bridges made when cysteine residues react with dehydroalanine or dehydrobutyrine moieties that have in turn been formed by dehydration of serine or threonine residues, respectively. The possession of lanthionine bridges defines cinnamycin as a lantibiotic. The lantibiotics studied so far are made as prepeptides, each consisting of a leader peptide and a propeptide. Modification of amino acid residues in the propeptide occurs before cleavage of the leader sequence, which releases the mature lantibiotic. In addition to lanthionine residues, lantibiotics may also contain other posttranslationally modified amino acid residues. Thus, cinnamycin contains a ␤-hydroxy-aspartate residue and a lysino-alanine bridge (apparently formed in a similar manner to a lanthionine bridge but with a lysine residue replacing cysteine; Fig. 1). Lantibiotic synthesis and classification have been reviewed (1).There are two major subclasses of lantibiotics. Type A lantibiotics have been studied intensively and have a tertiary structure that is relatively flexible and rod-like. In contrast, the less-studied type B lantibiotics have a relatively globular and inflexible tertiary structure (2). Whereas type A lantibiotics form pores in the cell membrane, type B lantibiotics may inhibit enzymes involved in cell-wall biosynthesis (3). Cinnamycin is closely related to type B lantibiotics duramycin, duramycin B, duramycin C, and ancovenin. These compounds are all derived from 19-aa propeptides and have lanthionine residues in similar position...

A physical map of the Streptococcus (Diplococcus ) pneumoniae chromosome, which is circular and 2,270 kbp in circumference, has been constructed. The restriction enzymes ApaI, SmaI, and SacII were used to digest intact chromosomes, and the fragments were resolved by field inversion gel electrophoresis (FIGE). The digests produced 22, 20, and 29 fragments, respectively. The order of the fragments was deduced from Southern blot hybridization of isolated labeled fragments to separated fragments of the various restriction digests. Genetic markers were correlated with the physical map by transformation of recipient cells with FIGE-isolated DNA fragments derived from genetically marked S. pneumoniae strains. In addition, markers were mapped by the hybridization of cloned genes to FIGE-separated restriction fragments. Six rRNA gene (rrn) clusters were mapped by hybridization to rrn-containing fragments of Haemophilus influenzae.Transformation of Streptococcus (Diplococcus) pneumoniae was the first method found to transfer genetic information in bacteria (1, 14), and it has had a monumental impact on the development of molecular biology. Although the pneumococcal transformation system has been extensively investigated for the past 45 years (6,17,40,41), understanding of its genetics and biochemistry, compared with that of Escherichia coli (2, 44) and/or Bacillus subtilis (16), is still relatively primitive. The absence of a genetic map has been a major impediment to the investigation of the molecular genetics of S. pneumoniae.The ability to separate large fragments of DNA by pulsedfield gel electrophoresis has provided the technology to map the chromosomes of bacteria (10, 19, 20, 25-27, 43, 44), and this technology has gained wide acceptance for analyzing the chromosomes of more complex organisms as well. The map of the S. pneumoniae chromosome should provide a useful framework for further molecular and genetic investigations. MATERIALS AND METHODSBacterial strains and growth conditions. All bacteria used in this study are derived from pneumococcus strain R6. A subculture of S. pneumoniae 800 or 801 was used in this study (28), along with a multiply marked strain (strain 119) resistant to 200 ,ug of streptomycin (str41) per ml, 75 ,ug of fusidic acid (fus-rA) per ml, 4 ,ug of novobiocin (nov-rl) per ml, 2 ,ug of optochin (opt-r2) per ml, 1 ,ug of rifampin (rif-rF) per ml, and 5 ,ug of streptolydigin (stg-rF) per ml (47). The uvr resistance gene (48) was located with the use of the cloned gene (42). To map the amiA gene, strain 801 bearing amiA3 was used (12). The methotrexate-sensitive bacteria in the resistant population were selected in synthetic medium containing an excess of isoleucine (40). The strain resistant to 0.1 ,ug of cefotaxime per ml was obtained by transforma- tion of strain 801 with DNA extracted from strain C506, which is resistant to a higher level of cefotaxime (1 ,ug/ml) (23). A second level of resistance (0.4 ,ug/ml) was obtained by transformation of a strain resistant to 0.1 ,ug of cefotaxime per ...

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