Fumitoshi Ishino

Evolution of an inducible penicillin-target protein in methicillin-resistant Staphylococcus aureus by gene fusion.

A new β‐lactam‐inducible penicillin‐binding protein (PBP) that has extremely low affinity to penicillin and most other β‐lactam antibiotics has been widely found in highly, β‐lactam(methicillin)‐resistant Staphylococcus aureus (MRSA). The gene for this protein was sequenced and the nucleotide sequence in its promoter and close upstream area was found to show close similarity with that of staphylococcal penicillinase, while the amino acid sequence over a wide range of the molecule was found to be similar to those of two PBPs of Escherichia coli, the shape‐determining protein (PBP 2) and septum‐forming one (PBP 3). Probably the MRSA PBP (M r 76462) evolved by recombination of two genes: an inducible type I penicillinase gene and a PBP gene of a bacterium, causing the formation of a β‐lactam‐inducible MRSA PBP.

Peptidoglycan synthetic enzyme activities of highly purified penicillin-binding protein 3 in Escherichia coli: A septum-forming reaction sequence

Abstract Highly purified penicillin-binding protein 3 of Escherichia coli was shown to synthesize crosslinked peptidoglycan from the lipid-linked precursor, N-acetylglucosaminyl-N-acetylmuramyl(-pentapeptide)-diphosphoryl undecaprenol through two successive enzymatic reactions, glycan chain extension by peptidoglycan transglycosylase and crossbridge formation by β-lactam sensitive peptidoglycan transpeptidase. These two enzyme activities seemed to be properties of protein 3. The transpeptidase reaction was specifically sensitive to the β-lactam antibiotics that inhibited the formation of the septum in vivo. These results indicate that the peptidoglycan-synthetic enzyme activities of penicillin-binding protein 3 may be involved in the process of cell division.

Dual enzyme activities of cell wall peptidoglycan synthesis, peptidoglycan transglycosylase and penicillin-sensitive transpeptidase, in purified preparations of Escherichia coli penicillin-binding protein 1A

Summary Two different cell wall peptidoglycan synthetase systems are carried by penicillin-binding proteins 1A and 1B purified from Escherichia coli. Both systems consist of two enzyme activities carrying out successive reactions of peptidoglycan synthesis from the lipid-linked precursor, N-acetylglucosaminyl-N-acetylmuramyl(-pentapeptide)-diphosphate-undecaprenol, namely, those of peptidoglycan transglycosylase and β-lactam antibiotic-sensitive transpeptidase. The activities of the two enzyme systems differ in optimal conditions and sensitivities to β-lactam antibiotics. The properties of purified PBP-1A are reported in this paper.

Nucleotide sequence involving murG and murC in the mra gene cluster region of Escherichia coli.

The mra (murein synthesis cluster a) region at 2 min on the Escherichia coli chromosome map carries the genes for peptidoglycan synthesis (1, 2): genes murC, murD, murE, murF and ddl, coding for five enzymes synthesizing UDP-Nacetylmuramyl-pentapeptide (L-alanyl-D-glutamyl-mesodiaminopimelyl-£>-alanyl-Z)-alanine) from UDP-N-acetylmuramic acid by sequential addition of appropriate amino acids. The genes pbpB and ftsW (3) that code for septum-peptidoglycan synthetic proteins, murG (4) which produces a protein of unknown function and an open reading frame ORF-Y (5) were also located in the mra region. In the present study, we determined the base sequences of the murG and murC genes located between JisW and ddl and thus completed the sequencing of the total 12 kb mra region which is flanked by a 5 kb region involving JisQ, JisA,ftsZ and envA. An open reading frame of 1065 bp capable of encoding a moderately hydrophobic peptide with 355 amino acid residues (Mw 37,814) was found for murG, and one of 1473 bp encoding a peptide with 491 amino acid residues (Mw 53,625) was found for murC. The proteins MurG and MurC were detected on SDS/PAGE in an in vitro protein synthesis system. Overlapping of the open reading frames of the murG-murC area and its flanking genes ftsWand ddl was observed. Considerable homologies were found in the deduced amino acid sequences of the product proteins of murC, D, £and F, i.e., four ligases that synthesize UDP-N-acetylmuramyl-pentapeptide, including putative ATP-binding domains GXXGKT/S (126-131 of MurC). MurG showed considerable homology with the corresponding region of the Bacillus subtilis chromosome.

A mecillinam-sensitive peptidoglycan crosslinking reaction in Escherichia, coli☆

Abstract The amidinopenicillin, mecillinam, induces the formation of spherical cells of Escherichia coli by inactivation of penicillin-binding protein 2 (PBP2). A mecillinam-sensitive peptidoglycan crosslinking reaction has been demonstrated in particulate membrane preparations from this organism. The activity was detected in membranes that contained elevated levels of PBP2 and in which crosslinking reactions due to all other PBPs had been inactivated with the cephamycin antibiotic, cefmetazole. The particulate membrane preparation catalyzed synthesis of peptidoglycan that was up to 20% crosslinked from nucleotide precursors. Crosslinkage of the peptidoglycan was inhibited 50% by 0.2 μg mecillinam per ml but was not inhibited by much higher concentrations of cephamycins, which have very low affinity for PBP2. The crosslinking reaction appears to be due to the transpeptidase activity of PBP2, which is implicated in the mechanism of cell shape determination, and is the killing target for mecillinam.

Formation of hyper-crosslinked peptidoglycan with multiple crosslinkages by a penicillin-binding protein, 1A, of Escherichia coli

Abstract Hyper-crosslinked peptidoglycan was synthesized in vitro by purified penicillin-binding protein 1A of Escherichia coli . The peptidoglycan formed was crosslinked up to 39%. About half the crosslinks were novel three-handed crossbridges whereas the other half were two-handed crossbridges that are the major constituents of normally crosslinked peptidoglycan of E. coli . The structure of the three-handed crossbridge constructed among three peptide side-chains of - l -alanyl- d -glutamyl-meso-diaminopimelyl- d -alanyl- d -alanine was deduced from several criteria. Probably penicillin-binding protein 1A is responsible for hyper-crosslinking of E. coli peptidoglycan in vivo .

Developmental Potential of Haploid‐derived Parthenogenetic Cells in Mouse Chimeric Embryos1

Studies were made on the contribution of haploid‐derived parthenogenetic cells to haploid parthenogenetic ↔ fertilized chimeric embryos on day 9 and 10 of pregnancy. In most cases, the contribution of haploid‐derived parthenogenetic cells to embryonic tissues was higher than that to extraembryonic tissues. The contribution of haploid‐derived cells to embryonic tissues of some chimeras was more than 90%. Chromosomal analysis showed that actively dividing cells in most chimeric embryos contained about 40 chromosomes, indicating that they were diploidized, as haploid parthenogenetic blastocysts have about 20 chromosomes. Results suggested that haploid‐derived parthehogenetic cells in chimeric embryos diploidized spontaneously after the blastocyst stage. These cells were capable of differentiating into most cell types of embryonic tissues, but scarcely differentiated into extraembryonic tissues of day 9 embryos. The fate of haploid‐derived parthenogenetic cells during postimplantational development was similar to that of diploid parthenogenetic cells that had been diploidized experimentally in the one‐cell stage.

Additional file 18: of Protein-restricted diet during pregnancy after insemination alters behavioral phenotypes of the progeny

List of genes that exhibited higher expression level in FA group relative to PR group in adult brain. Table also includes identifiers such as Probe name, PrimaryAccession ID, GeneSymbol, Gene ontology (GO), Gene description, chromosome number, P value in Tukeyâ s multiple comparison test adjusted by FDR, and mean fold change of expression level. (CSV 1 kb)