Publications

• Nucleotide sequence and functional analysis of the luxE gene encoding acyl-protein synthetase of the lux operon from Photobacterium leiognathi.

  Lin J.W., Chao Y.F., Weng S.F.

  Nucleotide sequence of the luxE gene GenBank Accession No. U66407 from Photobacterium leiognathi PL741 has been determined, and the amino acid sequence of acyl-protein synthetase encoded by the luxE gene is deduced. Nucleotide sequence reveals that the luxE gene encodes acyl-protein synthetase, wh ... >> More

  Nucleotide sequence of the luxE gene GenBank Accession No. U66407 from Photobacterium leiognathi PL741 has been determined, and the amino acid sequence of acyl-protein synthetase encoded by the luxE gene is deduced. Nucleotide sequence reveals that the luxE gene encodes acyl-protein synthetase, which is a component of the fatty acid reductase complex that is responsible for converting fatty acid to aldehyde as substrate in the luciferase-catalyzed bioluminescence reaction. The acyl-protein synthetase encoded by the luxE gene has a calculated M, 43,128 and comprises 373 amino acid residues. Alignment and comparison of acyl-protein synthetases from P. leiognathi, P. phosphoreum, Vibrio fischeri, V. harveyi and Xenorhabdus luminescens shows that they are homologous; there is 75.5% homologous (44.2% identity and 31.3% similarity) among these species. Functional analysis illustrates that the specific segment sequence lying before or in the luxE gene might from potential loops omega o omega e1, omega e2 as mRNA stability loop and/or for sub-regulation by alternative modulation in the lux operon. The gene order of the luxE gene in the lux and the lum operons is<--ter-lumQ-lumP-R&R-luxC-luxD-luxA-luxB -luxN-luxE-->(R&R: regulatory region; ter; transcriptional terminator), whereas the R&R is the regulatory region for the lum and the lux operons, and ter is the transcriptional terminator for the lum operon. << Less

  Biochem Biophys Res Commun 228:764-773(1996) [PubMed] [EuropePMC]

• Identification of the acyl transfer site of fatty acyl-protein synthetase from bioluminescent bacteria.

  Soly R.R., Meighen E.A.

  Fatty acid activation, transfer, and reduction by the fatty acid reductase multienzyme complex from Photobacterium phosphoreum to generate fatty aldehydes for the luminescence reaction is regulated by the interaction of the synthetase and reductase subunits of this complex. Identification of the s ... >> More

  Fatty acid activation, transfer, and reduction by the fatty acid reductase multienzyme complex from Photobacterium phosphoreum to generate fatty aldehydes for the luminescence reaction is regulated by the interaction of the synthetase and reductase subunits of this complex. Identification of the specific site involved in covalent transfer of the fatty acyl group between the sites of activation and reduction on the synthetase and reductase subunits, respectively, is a critical step in understanding how subunit interactions modulate the flow of fatty acyl groups through the fatty acid reductase complex. To accomplish this goal, the nucleotide sequence of the luxE gene coding for the acyl-protein synthetase subunit (373 amino acid residues) was determined and the conserved cysteinyl residues implicated in fatty acyl transfer identified. Using site-specific mutagenesis, each of the five conserved cysteine residues was converted to a serine residue, the mutated synthetases expressed in Escherichia coli, and the properties of the mutant proteins examined. On complementation of four of the mutants with the reductase subunit, the synthetase subunit was acylated and the acyl group could be reversibly transferred between the reductase and synthetase subunits, and fatty acid reductase activity was fully regenerated. As well, sensitivity of the acylated synthetases to hydroxylamine cleavage (under denaturation conditions to remove any conformational effects on reactivity) was retained, showing that a cysteine and not a serine residue was still acylated. However, substitution of a cysteine residue only ten amino acid residues from the carboxyl terminal (C364S) prevented acylation of the synthetase and regeneration of fatty acid reductase activity. Moreover, this mutant protein preserved its ability to activate fatty acid to fatty acyl-AMP but could not accept the acyl group from the reductase subunit, demonstrating that the C364S synthetase had retained its conformation and specifically lost the fatty acylation site. These results provide evidence that the flow of fatty acyl groups in the fatty acid reductase complex is modulated by interaction of the reductase subunit with a cysteine residue very close to the carboxyl terminal of the synthetase, which in turn acts as a flexible arm to transfer acyl groups between the sites of activation and reduction. << Less

  J. Mol. Biol. 219:69-77(1991) [PubMed] [EuropePMC]

• Fatty acyl-AMP as an intermediate in fatty acid reduction to aldehyde in luminescent bacteria.

  Rodriguez A., Meighen E.

  The acyl protein synthetase component (50K) of the fatty acid reductase complex from the luminescent system of Photobacterium phosphoreum has been found to catalyze the activation of fatty acid via formation of an enzyme bound acyl-AMP (carboxyphosphate mixed anhydride) immediately prior to the ac ... >> More

  The acyl protein synthetase component (50K) of the fatty acid reductase complex from the luminescent system of Photobacterium phosphoreum has been found to catalyze the activation of fatty acid via formation of an enzyme bound acyl-AMP (carboxyphosphate mixed anhydride) immediately prior to the acylation of the enzyme. PPi-ATP exchange and nucleotide binding experiments are dependent on fatty acid and indicate that the fatty acyl-AMP is directly formed and that an adenylated enzyme intermediate is not part of the mechanism. The formation of acyl-AMP from fatty acid and ATP is reversible with a standard free energy of -2 kcal/mol, and is dependent on Mg2+. The fatty acyl-AMP intermediate has been isolated and shown to be part of the pathway of fatty acid reduction. The 34K component of the complex, which strongly stimulates the acylation of the 50K protein by fatty acyl-AMP or fatty acid and ATP, is not required for the formation of acyl-AMP showing that it differentially affects the fatty acid activation and acylation steps catalyzed by the 50K protein. << Less

  J Biol Chem 260:771-774(1985) [PubMed] [EuropePMC]

• Resolution of the fatty acid reductase from Photobacterium phosphoreum into acyl protein synthetase and acyl-CoA reductase activities. Evidence for an enzyme complex.

  Riendeau D., Rodriguez A., Meighen E.

  J. Biol. Chem. 257:6908-6915(1982) [PubMed] [EuropePMC]