The growth of sensitive E. coli cells at low micromolar concentrations
The development of sensitive E. coli cells at low micromolar concentrations (five, six), processed McC doesn’t influence cell growth, even at millimolar concentrations (3, 7). As a result, the peptide chain enables processed McC function via a Trojan horse mechanism by promoting its active uptake by means of YejABEF. YejABEF is uniquely responsible for McC transport, considering that yej mutants are completely resistant to McC (four). The biological function of YejABEF (apart from McC transport) is presently unknown. In Salmonella, it confers resistance to some antimicrobial peptides and permits proliferation inside activated macrophages, thus contributing to virulence (8). The latter house may perhaps be related towards the truth that YejABEF interferes with peptide presentation on key histocompatibility complex (MHC) class I molecules (9).TThe peptide part of McC is encoded by the mccA gene. At seven codons, this gene is thought of to be the shortest all-natural gene recognized (ten). The MccA peptide sequence is MRTGNAN. In the course of McC maturation, MccA is C-terminally adenylated by the MccB synthetase (11). Bioinformatics searches identified MccB homologs in diverse bacteria, and in some situations, brief nearby genes that could code for substrate peptides have been also predicted (12, 13). Aside from the C-terminal asparagine residue, most predicted MccA-like peptides have no sequence similarity to every single other or to E. coli MccA. However, several predicted MccA-like peptides (from IFN-gamma Protein medchemexpress Helicobacter pylori, Bartonella, Lactobacillus, and Streptococcus) possess the similar length because the E. coli peptide. On the other hand, a 56-amino-acid-long cyanobacterial MccA peptide plus a 42-ami-Received 10 April 2015 Accepted 13 July 2015 Accepted manuscript posted online 20 July 2015 Citation Bantysh O, Serebryakova M, Zukher I, Kulikovsky A, Tsibulskaya D, Dubiley S, Severinov K. 2015. Enzymatic synthesis and functional characterization of bioactive microcin C-like compounds with altered peptide sequence and length. J Bacteriol 197:3133141. doi:10.1128/JB.00271-15. Editor: W. W. Metcalf Address correspondence to Konstantin Severinov, [email protected]. Copyright 2015, American Society for Microbiology. All Rights Reserved. doi:ten.1128/JB.IL-10 Protein Gene ID 00271-October 2015 Volume 197 NumberJournal of Bacteriologyjb.asm.orgBantysh et al.FIG 1 Structure of microcin C. The chemical structure with the part of the molecule corresponding to toxic processed McC (modified aspartyl-adenylate) released inside the cell is shown. The transport component, i.e., the first six residues on the MccA peptide, are indicated inside a single-letter amino acid code. The N-terminal methionine is formylated (f).no-acid-long peptide from Yersinia pseudotuberculosis are topic to terminal adenylation by their cognate MccB enzymes (13), suggesting that the length of MccB target peptides can exceed the seven amino acids characteristic of most mcc-like operons. In vitro adenylation of MRTGNAN peptide by recombinant E. coli MccB is quite efficient (11). The reaction proceeds in two measures. 1st, one ATP molecule is consumed to convert the terminal asparagine into succinimide. This activated intermediate is coupled with all the second ATP molecule, resulting inside a biologically active peptide adenylate with terminal aspartate (11). Inside the presence on the MccD and MccE enzyme pair, an aminopropyl group is attached for the item of MccB-catalyzed adenylation using Sadenosylmethionine (SAM) as a donor (14). The presence of aminopropyl increases the biological activity severalfold, possibly.
