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PubMed1978

Effect of antibiotics, non-ionic detergents, and vitamins on the osmotic barriers of Micrococcus glutamicus.

The production of amino acids by the mutant strain, homoserine methionine deficient, of Micrococcus glutamicus, was studied through the elucidation of the role of chemical agent affecting the osmotic barriers. Penicillin was found to affect the cell wall integrity and to increase greatly the total amino acid content, especially in presence of high biotin content. Non-ionic detergents were found to affect the integrity of cytoplasmic membrane. The effect was not similar with the different types of detergents and not proportional to the increase of its concentration.

Amino Acids↗
PubMed2003

Resuscitation factors from mycobacteria: homologs of Micrococcus luteus proteins.

SETTING: Resuscitation promoting factors (Rpfs) are proteins, originally identified in Micrococcus luteus, that promote recovery of bacteria from a viable but non-replicating phase (e.g., stationary phase or latency) to a replicating phase. Purified M. luteus Rpf can stimulate growth and increase recovery of M. luteus bacteria as well as Mycobacterium tuberculosis bacteria from prolonged stationary cultures. OBJECTIVE: To clone and characterize Rpfs from mycobacteria. DESIGN: We cloned one M. avium subsp. paratuberculosis rpf gene and one M. tuberculosis rpf gene into the pET19b or pET21a vector for expression in Escherichia coli. The His-tag recombinant proteins were purified and characterized. RESULTS: When the purified recombinant proteins were added to Sauton medium (a relatively minimal medium) at 100-500 pM, lag phase for mycobacteria from non-replicating cultures was shortened and there was a 10- to 100-fold increase in colony-forming units compared with control samples. In most probable number assays, the mycobacterial Rpfs increased recovery of mycobacteria from late stationary culture by about 10-fold. The Rpfs also promoted recovery of extensively washed Mycobacterium smegmatis bacteria inoculated into Sauton medium. Rpfs had only minor effects on growth of M. tuberculosis in BACTEC 12B broth, a rich medium. CONCLUSION: The mycobacterial Rpfs demonstrate resuscitation activities similar to those of the M. luteus Rpf.

Amino Acid Sequence↗
PubMed2003

A novel prodigiosin-like immunosuppressant from an alkalophilic Micrococcus sp.

A novel red pigment, 2,2'-[3-methoxy-1'amyl-5'-methyl-4-(1-pyrryl)] dipyrryl-methene (MAMPDM), which has properties similar to those of prodigiosins, has been isolated for the first time from a bacterium putatively identified as Micrococcus sp. Our studies showed that MAMPDM inhibited proliferation of both human T as well as B cells and murine T cells, in response to polyclonal mitogens, in a concentration-dependent manner while murine B cell proliferation induced by lipopolysaccharide was inhibited only at high concentration. The effect of MAMPDM on constitutive cell cycling was ascertained using four mouse and human tumour cell lines. At 100 nM, the concentration that inhibited con A induced proliferation of mouse spleen cells, the viability of these cell lines was not affected. At 10-100-fold higher concentration of MAMPDM, however, there was a decrease in cell viability with T cell-derived cell lines being more sensitive. MAMPDM did not block the secretion of IL-2 or expression of CD25 though it inhibited the proliferation of con A stimulated T cells. The higher amount of IL-2 in the supernatant of the con A stimulated T cells, cultured in the presence of the immunomodulator, indicated accumulation of IL-2 due to its reduced utilisation. At inhibitory concentration, MAMPDM induced apoptosis in con A stimulated cells. Thus, MAMPDM may have considerable and selective T cell immunosuppressive potential and appears to act by a mechanism distinct from that of other known immunosuppressors.

Alkenes↗
PubMed1993

EPR and ENDOR detection of compound I from Micrococcus lysodeikticus catalase.

We present the first EPR and ENDOR examination of a catalase compound I (Cat I), the one formed by peracetic acid treatment of Micrococcus lysodeikticus catalase. The Cat I rapid-passage EPR signal (g perpendicular eff = 3.32; g parallel eff approximately 2) appears quite different from those reported previously for the compounds I from horseradish peroxidase (HRP I) and chloroperoxidase. Nonetheless, all three signals can be explained by the same model for exchange coupling between an S = 1 oxoferryl [Fe = O]2+ moiety and a porphyrin pi-cation radical (S' = 1/2) (Schulz, C. E., et al. (1979) FEBS Lett. 103, 102-105). The signal for Cat I is unlike those for the two peroxidases in that it reflects a ferromagnetic rather than antiferromagnetic exchange. Preliminary 1H ENDOR spectra for Cat I appear to differ from the proton (1H) ENDOR spectra of HRP I; the latter, along with the 14N ENDOR spectra, indicate that the porphyrin radical in HRP I exhibits a predominantly A2u-like state having large spin densities on porphyrin N and C(beta). The proton ENDOR spectrum of Cat I is insensitive to H/D exchange, which indicates that the [Fe = O]2+ moiety is not protonated. Consideration of the EPR results for a series of compounds I suggests that the sign and magnitude of the exchange parameter (J) is correlated with the nature of the proximal axial ligand.

Catalase↗
PubMed1987

Selective inhibition by methoxyamine of the apurinic/apyrimidinic endonuclease activity associated with pyrimidine dimer-DNA glycosylases from Micrococcus luteus and bacteriophage T4.

The UV endonucleases [endodeoxyribonuclease (pyrimidine dimer), EC 3.1.25.1] from Micrococcus luteus and bacteriophage T4 possess two catalytic activities specific for the site of cyclobutane pyrimidine dimers in UV-irradiated DNA: a DNA glycosylase that cleaves the 5'-glycosyl bond of the dimerized pyrimidines and an apurinic/apyrimidinic (AP) endonuclease that thereupon incises the phosphodiester bond 3' to the resulting apyrimidinic site. We have explored the potential use of methoxyamine, a chemical that reacts at neutral pH with AP sites in DNA, as a selective inhibitor of the AP endonuclease activities residing in the M. luteus and T4 enzymes. The presence of 50 mM methoxyamine during incubation of UV- (4 kJ/m2, 254 nm) treated, [3H]thymine-labeled poly(dA).poly(dT) with either enzyme preparation was found to protect completely the irradiated copolymer from endonucleolytic attack at dimer sites, as assayed by yield of acid-soluble radioactivity. In contrast, the dimer-DNA glycosylase activity of each enzyme remained fully functional, as monitored retrospectively by release of free thymine after either photochemical- (5 kJ/m2, 254 nm) or photoenzymic- (Escherichia coli photolyase plus visible light) induced reversal of pyrimidine dimers in the UV-damaged substrate. Our data demonstrate that the inhibition of the strand-incision reaction arises because of chemical modification of the AP sites and is not due to inactivation of the enzyme by methoxyamine. Our results, combined with earlier findings for 5'-acting AP endonucleases, strongly suggest that methoxyamine is a highly specific inhibitor of virtually all AP endonucleases, irrespective of their modes of action, and may therefore prove useful in a wide variety of DNA repair studies.

DNA Glycosylases↗
PubMed1987

Mechanism of action of Micrococcus luteus gamma-endonuclease.

Micrococcus luteus extracts contain gamma-endonuclease, a Mg2+-independent endonuclease that cleaves gamma-irradiated DNA. This enzyme has been purified approximately 1000-fold, and the purified enzyme was used to study its substrate specificity and mechanism of action. gamma-Endonuclease cleaves DNA containing either thymine glycols, urea residues, or apurinic sites but not undamaged DNA or DNA containing reduced apurinic sites. The enzyme has both N-glycosylase activity that releases thymine glycol residues from OsO4-treated DNA and an associated apurinic endonuclease activity. The location and nature of the cleavage site produced has been determined with DNA sequencing techniques. gamma-Endonuclease cleaves DNA containing thymine glycols or apurinic sites immediately 3' to the damaged or missing base. Cleavage results in a 5'-phosphate terminus and a 3' baseless sugar residue. Cleavage sites can be converted to primers for DNA polymerase I by subsequent treatment with Escherichia coli exonuclease III. The mechanism of action of gamma-endonuclease and its substrate specificity are very similar to those identified for E. coli endonuclease III.

Base Sequence↗
PubMed1987

Dynamic interaction between components of hexaprenyl diphosphate synthase from Micrococcus luteus BP-26.

Hexaprenyl diphosphate synthase from Micrococcus luteus BP-26, which has been known to be dissociated into two essential components, designated as components A and B, during hydroxyapatite chromatography [Fujii, H., Koyama, T., & Ogura, K. (1982) J. Biol. Chem. 257, 14610-14612], was also resolved similarly by Sephadex G-100 or DEAE ion-exchange chromatography. Each component takes various self-aggregated forms. The apparent molecular mass of component B estimated by gel filtration on Superose 12 varied depending on its concentration, ranging from approximately 18 to 49 kilodaltons (kDa). On the other hand, the apparent molecular mass of component A varied depending on not only its concentration but also the ionic strength of the medium, ranging from approximately 13 to 24 kDa. When a mixture of components A and B preincubated in the presence of Mg2+ but in the absence of substrate was subjected to Superose 12 gel filtration, they were eluted at positions identical with those observed when they were chromatographed individually. In contrast, when a mixture of components A and B incubated in the presence of Mg2+ and substrates was filtrated on Superose 12, the elution positions were markedly changed, showing that an approximately 24-kDa aggregate of component A (designated as A) and an approximately 27-kDa aggregate of component B (designated as B) were the major species. Evidence was also obtained to show that farnesyl diphosphate (FPP) binds to the components to form an aggregate, A-B-FPP-Mg2+, which probably represents an intermediary state of enzyme catalysis.

Alkyl and Aryl Transferases↗
PubMed1989

Transverse and lateral distribution of phospholipids and glycolipids in the membrane of the bacterium Micrococcus luteus.

The photodimerization of anthracene was used to investigate the transverse and lateral distribution of lipids in the membrane of the Gram-positive bacterium Micrococcus luteus. 9-(2-Anthryl)nonanoic acid (9-AN) is incorporated at a high rate into various membrane lipids of M. luteus. On irradiation of intact bacteria at 360 nm, anthracene-labeled lipids form stable photodimers which can be extracted and separated by thin-layer chromatography. We present here the results of a study on the distribution of two major lipids, phosphatidylglycerol (PG) and dimannosyldiacylglycerol (DMDG), within each leaflet of the membrane lipid bilayer. After metabolic incorporation of a tritiated derivative of 9-AN in M. luteus, the radioactivity associated with the photodimers issued from PG and DMDG was counted. In the bacterial membrane, the ratio of PG-DMDG heterodimer with respect to PG-PG and DMDG-DMDG homodimers is around half of what should be obtained for a homogeneous mixture of the two lipids. In order to find out whether this was due to an asymmetric distribution of the two lipids between the two membrane leaflets or a heterogeneous distribution of the two lipids within the same membrane leaflet, the transverse distribution of PG and DMDG was also investigated. This was carried out by following the kinetics of oxidation of the two lipids by periodic acid in the membrane of M. luteus protoplasts. PG predominated slightly in the outer layer (60%), while DMDG was found to be symmetrically distributed between the two leaflets. By itself, this lipid asymmetry cannot account for the lipid distribution determined from the photodimerization experiments. This indicates that PG and DMDG are not homogeneously distributed in the plane of the bacterial membrane.

Anthracenes↗
PubMed1981

Poly(adenosine diphosphoribose) synthesis in ultraviolet-irradiated xeroderma pigmentosum cells reconstituted with Micrococcus luteus UV endonuclease.

Synthesis of DNA and poly(adenosine diphosphoribose) [poly(ADPR)] was examined in permeabilized xeroderma pigmentosum lymphoblasts (XP3BE) before and after UV irradiation and in the presence and absence of Micrococcus luteus UV endonuclease. M. luteus UV endonuclease had no effect on the level of DNA or poly(ADPR) synthesis in control, unirradiated cells. UV irradiation caused a decrease in replicative DNA synthesis without any significant change in poly(ADPR) synthesis. In UV-irradiated cells treated with M. luteus UV endonuclease, DNA synthesis was restored to a level slightly greater than in the unirradiated control cells, and poly(ADPR) synthesis increased by 2- to 4-fold. Time--course studies showed that the UV endonuclease dependent poly(ADPR) synthesis preceded the endonuclease-dependent DNA synthesis. Inhibition of endonuclease-dependent poly(ADPR) synthesis with 3-aminobenzamide, 5-methylnicotinamide, or theophylline produced a partial inhibition of the endonuclease-dependent DNA synthesis. Conversely, inhibition of the endonuclease-dependent DNA synthesis with dideoxythymidine triphosphate, phosphonoacetic acid, or aphidicolin had no effect on the endonuclease-dependent poly(ADPR) synthesis. These studies show that stimulation of poly(ADPR) synthesis in UV-irradiated cells occurs subsequent to the DNA strand breaks created by the specific action of the UV endonuclease on UV-irradiated DNA. The effect of the inhibitors of poly(ADPR) synthesis in UV-irradiated cells indicates that the endonuclease-stimulated DNA synthesis is dependent in part on the prior synthesis of poly(ADPR).

Cell Line↗
PubMed1981

Carbon-13 nuclear magnetic resonance spectroscopic study of teichuronic acid from Micrococcus luteus cell walls. Comparison of the polysaccharide isolated from cells with that synthesized in vitro.

Teichuronic acid isolated from the cell walls of Micrococcus luteus has been examined by natural-abundance (13)C NMR spectroscopy. Proton-decoupled and proton-coupled spectra were obtained for native teichuronic acid and also after the teichuronic acid had been oxidized with periodate and reduced with borohydride. The spectra are consistent with the structure [ManNAcUAp-( beta -1,6)-G1cp-( alpha -1,4)]n. Teichuronic acid synthesized in vitro from suitable substrates by the particulate enzyme fraction obtained from M. luteus yielded a (13)C NMR spectrum which is indistinguishable from that of the native teichuronic acid, indicating a structural identity of the teichuronic acid synthesized in vitro with that isolated from cell walls.

Cell Wall↗
PubMed1982

On the mechanism of de novo polymerization by form I polynucleotide phosphorylase of Micrococcus luteus.

The diastereomers of adenosine 5'-O-(1-thiodiphosphate) (ADP alpha S) have been tested as substrates for the polymerization reaction of primer-independent polynucleotide phosphorylase from Micrococcus luteus. The preferred substrate is ADP alpha S(Sp), which has a similar Km and a greatly reduced Vmax when compared to the natural substrate ADP. The other diastereomer, ADP alpha S(Rp), is preferentially cleaved by a polyphosphate kinase activity (present with the phosphorylase) that may be responsible for the removal of the 5'-beta-phosphate during de novo polymerization, leading to the observed 5'-phospho-poly(A). Inhibitor studies suggest that the kinase and de novo polymerization sites are not coincident. During de novo polymerization of the diastereomeric mixture, ADP alpha S(Rp) is selectively used to form 5' termini, whereas ADP alpha S(Sp) serves to support the chain elongation. Thus there are two stereochemically distinct subsites for initiating polymerization. ADP beta S functions as a substrate for polynucleotide phosphorylase with kinetic properties similar to those of ADP, indicating that removal of the beta-phosphate (a thiophosphate) is not a kinetically important step and probably occurs after polymerization is complete. The average chain length of the polymeric product is considerably smaller for ADP alpha S vs. ADP beta S or ADP, suggesting that the degree of processivity of the polymerization is determined by competition between the rate of polymerization and the rate of dissociation of the growing chain.

Adenosine Diphosphate↗
PubMed1980

Conversion of o-succinylbenzoate to dihydroxynaphthoate by extracts of Micrococcus luteus.

Cell-free extracts were prepared from either freshly grown or spray-dried cells of Micrococcus luteus ATCC 4698 by treatment with deoxyribonuclease and lysozyme. These extracts converted o-succinylbenzoic acid (OSB) to 1,4-dihydroxy-2-naphthoic acid (DHNA) as shown by spectrophotofluorometric and radioactivity assays. The conversion required the presence of ATP, CoA, and Mg2+. By use of [2-14C]OSB, the simultaneous production of the spirodilactone form of OSB was also demonstrated. The two products formed from OSB was also demonstrated. The two products formed from OSB were further characterized by gas chromatography combined with mass spectrometry. The production of the spirodilactone was suppressed by the addition of a preparation of the enzyme DHNA synthase obtained from Mycobacterium phlei. (This enzyme catalyzes the conversion of a CoA derivative of OSB to DHNA.) On mild acid treatment, the M. luteus extracts retained the ability to produce spirodilactone but lost the ability to form DHNA. These results are interpreted to mean that an OSB-CoA derivative is an intermediate in the conversion of OSB to DHNA by M. luteus and that two enzymes are involved, one to form the OSB-CoA derivative and the second to carry out a cyclization reaction.

Deoxyribonucleases↗
PubMed1980

Micrococcus luteus endonucleases for apurinic/apyrimidinic sites in deoxyribonucleic acid. 1. Purification and general properties.

Two chromatographically distinct endonucleases from Micrococcus luteus, specific for apurinic and apyrimidinic sites (AP-endonucleases A and B), have been extensively purified and characterized. Both are free from DNA glycosylase, unspecific endonuclease, and phosphatase activities. The two enzymes behave as monomeric proteins of approximately 35000 daltons. In addition to their different chromatographic properties on CM-cellulose, P-cellulose, hydroxylapatite, and DNA--Sepharose, both AP-endonucleases can be distinguished as follows: AP-endonuclease A has an isoelectric point of 4.8, shows a half-life of 4 min at 45 degrees C, reacts optimally at pH 7.5 and has a KM value of 2.3 X 10(-6) M. AP-endonuclease B has a pI of 8.8, is more stable at 45 degrees C (half-life of 10 min), and reacts optimally between pH 6.5 and pH 8.5; its KM value is 3.7 X 10(-6) M.

Chromatography, DEAE-Cellulose↗
PubMed1980

Micrococcus luteus endonucleases for apurinic/apyrimidinic sites in deoxyribonucleic acid. 2. Further studies on the substrate specificity and mechanism of action.

Two endonucleases specific for DNA-containing apurinic or apyrimidinic sites (AP-endonucleases A and B) have been isolated from Micrococcus luteus and highly purified. These enzymes have no exonuclease activity. Both AP-endonucleases hydrolyze DNA-containing apurinic or apyrimidinic sites at the 5' end of the lesion, thus generating 3'-hydroxyl and 5'-phosphoryl end groups. DNA-containing pyrimidine dimers, introduced at low doses of UV, are not hydrolyzed, whereas DNA-containing lesions, introduced at high doses of UV or by gamma irradiation are nicked by either AP-endonuclease. During hydrolysis of apurinic DNA, neither of the AP-endonucleases acts as a processive enzyme.

DNA, Viral↗
PubMed1978

Sequence of a rabbit anti-Micrococcus lysodeikticus antibody light chain.

The complete sequence of rabbit antibody light-chain L 120 has been elucidated. The antibody was raised against Micrococcus lysodeikticus bacteria and is specific for the external part of the cell wall. All protein used in this work was obtained from a single 50-mL bleeding. The variable region of L 120 is compared to 13 other sequences of chains of different specificities. The constant region of this b4 k chain is identical to that of two other constant regions published earlier. The general structure of the rabbit light chain is compatible with the three-dimensional folding proposed for human myeloma chains.

Amino Acid Sequence↗
PubMed1977

Solanesyl pyrophosphate synthetase from Micrococcus lysodeikticus.

Solanesyl pyrophosphate synthetase from extracts of Micrococcus lysodeikticus was purified by DEAE-Sephadex, hydroxylapatite, and Sephadex G-100 chromatography. This enzyme was found to catalyze the trans condensation of isopentenyl pyrophosphate with geranyl pyrophosphate to afford all-trans-octaprenyl (C40) and alltrans-nonaprenyl (C45) pyrophosphate without accumulation of prenyl pyrophosphate with chain length shorter than C40. all-trans-Farnesyl and all-trans-geranylgeranyl pyrophosphate also were active as cosubstrates, though they were less effective than geranyl pyrophosphate. However, neither dimethylallyl nor cis,trans,trans-geranylgeranyl pyrophosphate was active. The molecular weight of this enzyme was estimated to be 78 000 by Sephadex G-100 filtration. An enzyme preparation from young shoots of potato was found to hydrolyze the polyprenyl pyrophosphates effectively to give the corresponding prenols.

Alkyl and Aryl Transferases↗
PubMed2003

Mutational analysis of allylic substrate binding site of Micrococcus luteus B-P 26 undecaprenyl diphosphate synthase.

Undecaprenyl diphosphate (UPP) synthase catalyzes the sequential cis-condensation of isopentenyl diphosphate (IPP) onto (E,E)-farnesyl diphosphate (FPP). In our previous reports on the Micrococcus luteus B-P 26 UPP synthase, we have shown that the conserved residues in the disordered region from Ser-74 to Val-85 is crucial for the binding of FPP and the catalytic function [Fujikura, K., et al. (2000) J. Biochem. (Tokyo) 128, 917-922] and the existence of a structural P-loop motif for the FPP binding site [Fujihashi, M., et al. (2001) Proc. Natl. Acad. Sci. U.S.A., 98, 4337-4342]. To elucidate the allylic substrate binding site in more detail, we prepared eight mutant enzymes and examined their kinetic behavior. The mutant with respect to the two complementarily conserved Arg residues among the structural P-loop motif, G32R-R42G, retained the activity and showed product distribution pattern exactly similar to that of the wild-type, indicating that the complementarily conserved Arg is important for maintaining the catalytic function. Substitutions of Asp-29, Arg-33, or Arg-80 with Ala resulted in a large loss of enzyme activity, suggesting that these residues are essential for catalytic function. However, the K(m) values of these mutant enzymes for Z-GGPP, which is the first intermediate during the enzymatic cis-condensations of IPP onto FPP, were only moderately different or little changed from those of the wild type. These results suggest that the binding site for the intermediate Z-GGPP having a cis double bond is different to that for the intrinsic allylic substrate, FPP, whose diphosphate moiety is recognized by the structural P-loop.

Alkyl and Aryl Transferases↗
PubMed1989

Inhibition of 125I-labeled ristocetin binding to Micrococcus luteus cells by the peptides related to bacterial cell wall mucopeptide precursors: quantitative structure-activity relationships.

Quantitative structure-activity relationships (QSAR) of N-Ac amino acids, N-Ac dipeptides, and N-Ac tripeptides in inhibition of 125I-labeled ristocetin binding to Micrococcus luteus cell wall have been developed to probe the details of the binding between ristocetin and N-acetylated peptides. The correlation equations indicate that (1) the binding is stronger for peptides in which the side chain of the C-terminal amino acid has a large molar refractivity (MR) value, (2) the binding is weaker for peptides with polar than for those with nonpolar C-terminal side chains, (3) the N-terminal amino acid in N-Ac dipeptides contributes 12 times that of the C-terminal amino acid to binding affinity, and (4) the interactions between ristocetin and the N-terminal amino acid of N-acetyl tripeptides appear to be much weaker than those with the first two amino acids.

Acetylation↗