Logo of pnasPNASInfo for AuthorsSubscriptionsAboutThis Article
Proc Natl Acad Sci U S A. Sep 3, 1996; 93(18): 9505–9509.

Generation of cell-to-cell signals in quorum sensing: acyl homoserine lactone synthase activity of a purified Vibrio fischeri LuxI protein.


Many bacteria use acyl homoserine lactone signals to monitor cell density in a type of gene regulation termed quorum sensing and response. Synthesis of these signals is directed by homologs of the luxi gene of Vibrio fischeri. This communication resolves two critical issues concerning the synthesis of the V. fischeri signal. (i) The luxI product is directly involved in signal synthesis-the protein is an acyl homoserine lactone synthase; and (ii) the substrates for acyl homoserine lactone synthesis are not amino acids from biosynthetic pathways or fatty acid degradation products, but rather they are S-adenosylmethionine (SAM) and an acylated acyl carrier protein (ACP) from the fatty acid biosynthesis pathway. We purified a maltose binding protein-LuxI fusion polypeptide and showed that, when provided with the appropriate substrates, it catalyzes the synthesis of an acyl homoserine lactone. In V. fischeri, luxi directs the synthesis of N-(3-oxohexanoyl) homoserine lactone and hexanoyl homoserine lactone. The purified maltose binding protein-LuxI fusion protein catalyzes the synthesis of hexanoyl homoserine lactone from hexanoyl-ACP and SAM. There is a high level of specificity for hexanoyl-ACP over ACPs with differing acyl group lengths, and hexanoyl homoserine lactone was not synthesized when SAM was replaced with other amino acids, such as methionine, S-adenosylhomocysteine, homoserine, or homoserine lactone, or when hexanoyl-SAM was provided as the substrate. This provides direct evidence that the LuxI protein is an auto-inducer synthase that catalyzes the formation of an amide bond between SAM and a fatty acyl-ACP and then catalyzes the formation of the acyl homoserine lactone from the acyl-SAM intermediate.

Full text

Full text is available as a scanned copy of the original print version. Get a printable copy (PDF file) of the complete article (1.0M), or click on a page image below to browse page by page. Links to PubMed are also available for Selected References.

Images in this article

Click on the image to see a larger version.

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Fuqua WC, Winans SC, Greenberg EP. Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcriptional regulators. J Bacteriol. 1994 Jan;176(2):269–275. [PMC free article] [PubMed]
  • Salmond GP, Bycroft BW, Stewart GS, Williams P. The bacterial 'enigma': cracking the code of cell-cell communication. Mol Microbiol. 1995 May;16(4):615–624. [PubMed]
  • Sitnikov DM, Schineller JB, Baldwin TO. Transcriptional regulation of bioluminesence genes from Vibrio fischeri. Mol Microbiol. 1995 Sep;17(5):801–812. [PubMed]
  • Eberhard A, Burlingame AL, Eberhard C, Kenyon GL, Nealson KH, Oppenheimer NJ. Structural identification of autoinducer of Photobacterium fischeri luciferase. Biochemistry. 1981 Apr 28;20(9):2444–2449. [PubMed]
  • Nealson KH, Platt T, Hastings JW. Cellular control of the synthesis and activity of the bacterial luminescent system. J Bacteriol. 1970 Oct;104(1):313–322. [PMC free article] [PubMed]
  • Kuo A, Blough NV, Dunlap PV. Multiple N-acyl-L-homoserine lactone autoinducers of luminescence in the marine symbiotic bacterium Vibrio fischeri. J Bacteriol. 1994 Dec;176(24):7558–7565. [PMC free article] [PubMed]
  • Hanzelka BL, Greenberg EP. Evidence that the N-terminal region of the Vibrio fischeri LuxR protein constitutes an autoinducer-binding domain. J Bacteriol. 1995 Feb;177(3):815–817. [PMC free article] [PubMed]
  • Engebrecht J, Nealson K, Silverman M. Bacterial bioluminescence: isolation and genetic analysis of functions from Vibrio fischeri. Cell. 1983 Mar;32(3):773–781. [PubMed]
  • Eberhard A, Widrig CA, McBath P, Schineller JB. Analogs of the autoinducer of bioluminescence in Vibrio fischeri. Arch Microbiol. 1986 Oct;146(1):35–40. [PubMed]
  • Schaefer AL, Hanzelka BL, Eberhard A, Greenberg EP. Quorum sensing in Vibrio fischeri: probing autoinducer-LuxR interactions with autoinducer analogs. J Bacteriol. 1996 May;178(10):2897–2901. [PMC free article] [PubMed]
  • Huisman GW, Kolter R. Sensing starvation: a homoserine lactone--dependent signaling pathway in Escherichia coli. Science. 1994 Jul 22;265(5171):537–539. [PubMed]
  • Stewart V, Parales J., Jr Identification and expression of genes narL and narX of the nar (nitrate reductase) locus in Escherichia coli K-12. J Bacteriol. 1988 Apr;170(4):1589–1597. [PMC free article] [PubMed]
  • Pearson JP, Gray KM, Passador L, Tucker KD, Eberhard A, Iglewski BH, Greenberg EP. Structure of the autoinducer required for expression of Pseudomonas aeruginosa virulence genes. Proc Natl Acad Sci U S A. 1994 Jan 4;91(1):197–201. [PMC free article] [PubMed]
  • Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. [PMC free article] [PubMed]
  • Piper KR, Beck von Bodman S, Farrand SK. Conjugation factor of Agrobacterium tumefaciens regulates Ti plasmid transfer by autoinduction. Nature. 1993 Apr 1;362(6419):448–450. [PubMed]
  • Shen Z, Fice D, Byers DM. Preparation of fatty-acylated derivatives of acyl carrier protein using Vibrio harveyi acyl-ACP synthetase. Anal Biochem. 1992 Jul;204(1):34–39. [PubMed]
  • Keating DH, Carey MR, Cronan JE., Jr The unmodified (apo) form of Escherichia coli acyl carrier protein is a potent inhibitor of cell growth. J Biol Chem. 1995 Sep 22;270(38):22229–22235. [PubMed]
  • Lapidot Y, Rappoport S, Wolman Y. Use of esters of N-hydroxysuccinimide in the synthesis of N-acylamino acids. J Lipid Res. 1967 Mar;8(2):142–145. [PubMed]
  • Moré MI, Finger LD, Stryker JL, Fuqua C, Eberhard A, Winans SC. Enzymatic synthesis of a quorum-sensing autoinducer through use of defined substrates. Science. 1996 Jun 14;272(5268):1655–1658. [PubMed]
  • PARKS LW, SCHLENK F. Formation of alpha-amino-gamma-butyrolactone from S-adenosylmethionine. Arch Biochem Biophys. 1958 May;75(1):291–292. [PubMed]
  • Hoffman JL. Chromatographic analysis of the chiral and covalent instability of S-adenosyl-L-methionine. Biochemistry. 1986 Jul 29;25(15):4444–4449. [PubMed]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences


Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...