This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Qadri, S. M. H. Articles by Williams, R. P. Search for Related Content PubMed PubMed Citation Articles by Qadri, S. M. H. Articles by Williams, R. P.

Role of Methionine in Biosynthesis of Prodigiosin by Serratia marcescens

Department of Microbiology and Immunology, Baylor College of Medicine, Houston, Texas 77025

ABSTRACT

Methionine alone did not allow biosynthesis of prodigiosin (2-methyl-3-amyl-6-methoxyprodigiosene) in nonproliferating cells (NPC) of Serratia marcescens strain Nima. However, when methionine was added to NPC synthesizing prodigiosin in the presence of other amino acids, the lag period for synthesis of prodigiosin was shortened, an increased amount of the pigment was formed, and the optimal concentrations of the other amino acids were reduced. Less prodigiosin was synthesized when addition of methionine was delayed beyond 4 h. The specific activity of prodigiosin synthesized by addition of ¹⁴CH₃-methionine was 40 to 50 times greater than that synthesized from methionine-2-¹⁴C or ¹⁴COOH-methionine. NPC of mutant OF of S. marcescens synthesized norprodigiosin (2-methyl-3-amyl-6-hydroxyprodigiosene), and the specific activity of this pigment synthesized in the presence of ¹⁴CH₃-methionine was only 5 to 13 times greater than that synthesized from methionine-2-¹⁴C or ¹⁴COOH-methionine. A particulate, cell-free extract of mutant WF of S. marcescens methylated norprodigiosin to form prodigiosin. When the extract was added to NPC of mutant OF synthesizing norprodigiosin in the presence of ¹⁴CH₃-methionine, the prodigiosin formed had 80% greater specific activity than the norprodigiosin synthesized in the absence of the extract. The C6 hydroxyl group of norprodigiosin was methylated in the presence of the extract and methionine. Biosynthesis of prodigiosin by NPC of strain Nima also was augmented by addition of S-adenosylmethionine. Various analogues of methionine such as norleucine, norvaline, ethionine, and -methylmethionine did not affect biosynthesis of prodigiosin by NPC either in the presence or absence of methionine.