The F1Fo-ATP synthase of Mycobacterium smegmatis is essential for growth.

The F(1)F(o)-ATP synthase plays an important role in a number of vital cellular processes in plants, animals, and microorganisms. In this study, we constructed a DeltaatpD mutant of Mycobacterium smegmatis and demonstrated that atpD encoding the beta subunit of the F(1)F(o)-ATP synthase is an essential gene in M. smegmatis during growth on nonfermentable and fermentable carbon sources.

Catalytic enantioselective indium-mediated allylation of hydrazones.

[reaction: see text] A facile and highly selective indium-mediated allylation of hydrazones utilizing BINOL ligands is described. Chiral (R)-3,3'-bistrifluoromethylBINOL afforded homoallylic amines in up to 97% ee with stoichiometric ligand. Employing only 10 mol % ligand afforded selectivity of up to 92% ee.

Mutants of Mycobacterium smegmatis unable to grow at acidic pH in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone.

Mycobacterium smegmatis is able to grow and survive at acidic pH, and exhibits intracellular pH homeostasis under these conditions. In this study, the authors have identified low proton permeability of the cytoplasmic membrane, and high cytoplasmic buffering capacity, as determinants of intrinsic acid resistance of M. smegmatis.

Morphotypic conversion in Listeria monocytogenes biofilm formation: biological significance of rough colony isolates.

Adherence to a stainless steel surface selected isolates of Listeria monocytogenes with enhanced surface colonization abilities and a change in phenotype from the common smooth colony morphology to a succession of rough colony morphotypes. Growth in broth culture of the best-adapted, surface-colonizing rough colony morphotype gave a smooth colony revertant. Comparative analysis revealed that the smooth and rough variants had similar phenotypic and biochemical characteristics (e.

Bacterial Na+ - or H+ -coupled ATP synthases operating at low electrochemical potential.

In certain strictly anaerobic bacteria, the energy for growth is derived entirely from a decarboxylation reaction. A prominent example is Propionigenium modestum, which converts the free energy of the decarboxylation of (S)-methylmalonyl-CoA to propionyl-CoA (DeltaG degrees =-20.6 kJ/mol) into an electrochemical Na(+) ion gradient across the membrane.

Membrane topology and mutational analysis of Escherichia coli CydDC, an ABC-type cysteine exporter required for cytochrome assembly.

Cytochrome bd is a respiratory quinol oxidase in Escherichia coli. Besides the structural genes (cydA and cydB) encoding the oxidase complex, the cydD and cydC genes, encoding an ABC-type transporter, are required for assembly of this oxidase. Recently, cysteine has been identified as a substrate (allocrite) that is transported from the cytoplasm by CydDC, but the mechanism of cysteine export to the periplasm and its role there remain unknown.

Persistence of vancomycin-resistant enterococci in New Zealand broilers after discontinuation of avoparcin use.

Large amounts of tylosin, zinc-bacitracin, and avilamycin are currently used as prophylactics in New Zealand broiler production. Avoparcin was also used from 1977 to 2000. A total of 382 enterococci were isolated from 213 fecal samples (147 individual poultry farms) using enrichment broths plated on m-Enterococcus agar lacking antimicrobials.

Acquired bacitracin resistance in Enterococcus faecalis is mediated by an ABC transporter and a novel regulatory protein, BcrR.

Bacitracin resistance (bacitracin MIC, >/=256 microg ml(-1)) has been reported in Enterococcus faecalis, and in the present study we report on the genetic basis for this resistance. Mutagenesis was carried out with transposon Tn917 to select for E. faecalis mutants with decreased resistance to bacitracin.

Synthesis and evaluation of novel oxazoline MMP inhibitors.

MMP inhibitors with novel oxazoline zinc binding groups have been synthesized and evaluated. Selectivity for the inhibition of MMP-9 over MMP-1, MMP-2, and MMP-12 has been achieved in several cases.

Vancomycin-induced deletion of the methicillin resistance gene mecA in Staphylococcus aureus.

Objective: To elucidate factors that contribute to the development of vancomycin resistance in methicillin-resistant Staphylococcus aureus (MRSA).

Methods: Forty-nine MRSA isolates were subjected to passage selection with vancomycin to isolate mutants with reduced susceptibility to vancomycin. One mutant was chosen for detailed molecular and biochemical characterization.

Nitrogen heterocycles via palladium-catalyzed carbocyclization. Formal synthesis of (+)-alpha-allokainic acid.

[reaction: see text] The Pd-catalyzed carbocyclization of ketoamides was investigated and found to be highly dependent on the phosphine ligand as well as the presence of coordinating counterions. Nitrogen heterocycles were formed without erosion of the stereochemical integrity. The utility of the lactam products was demonstrated by the formal synthesis of (+)-alpha-allokainic acid.

Renal cysts of inv/inv mice resemble early infantile nephronophthisis.

Cystic kidney disease has been linked to mutations in the Invs gene in mice with inversion of embryonic turning (inv/inv) and the INVS (NPHP2) gene in infants with nephronophthisis type 2 (NPHP2). The inv mouse model features multiorgan defects including renal cysts, altered left-right laterality, and hepatobiliary duct malformations transmitted in an autosomal recessive manner. Affected mice usually die of renal and liver failure by postnatal day 7.

Highly diastereoselective indium-mediated allylation of chiral hydrazones.

The indium-mediated allylation of chiral hydrazones was investigated. Essentially complete diastereoselectivity and quantitative yields were obtained for substrates derived from both aromatic and aliphatic aldehydes. [reaction--see text]

Isolation and characterization of arsenate-reducing bacteria from arsenic-contaminated sites in New Zealand.

Two environmental sites in New Zealand were sampled (e.g., water and sediment) for bacterial isolates that could use either arsenite as an electron donor or arsenate as an electron acceptor under aerobic and anaerobic growth conditions, respectively.

Cloning and molecular characterization of the atp operon encoding for the F1F0-ATP synthase from a thermoalkaliphilic Bacillus sp. strain TA2.A1.

The genes encoding the subunits for the F(1)F(0)-ATP synthase from Bacillus sp. strain TA2.A1 were cloned as three overlapping fragments and sequenced.

Purification and biochemical characterization of the F1Fo-ATP synthase from thermoalkaliphilic Bacillus sp. strain TA2.A1.

We describe here purification and biochemical characterization of the F(1)F(o)-ATP synthase from the thermoalkaliphilic organism Bacillus sp. strain TA2.A1.

Characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolate from a dog with mastitis: further evidence of a clonal lineage of VREF in New Zealand.

We report here on the characterization of a vancomycin-resistant Enterococcus faecalis (VREF) isolated from a dog with mastitis. The isolate was positive for the vanA, ermB, and tet(M) genes, with vanA and ermB carried on the same transferable plasmid. Comparison of this isolate with VREF from poultry and human sources in New Zealand demonstrated identical SmaI macrorestriction patterns and Tn1546-like elements.

Hydrogen bond directed highly regioselective palladium-catalyzed allylic substitution.

The palladium-catalyzed allylic substitution of 5-vinyloxazolidinones and derivatives was investigated. Unusual and high regioselectivity for the branched product was observed. The regioselectivity was influenced by the type of substrate, the solvents, and the nucleophile.

Bioenergetic properties of the thermoalkaliphilic Bacillus sp. strain TA2.A1.

The thermoalkaliphilic Bacillus sp. strain TA2.A1 was able to grow in pH-controlled batch culture containing a nonfermentable growth substrate from pH 7.

A clonal lineage of VanA-type Enterococcus faecalis predominates in vancomycin-resistant Enterococci isolated in New Zealand.

Avoparcin was used as a feed additive in New Zealand broiler production from 1977 until June 2000. We report here on the effects of the usage and discontinuation of avoparcin on the prevalence of vancomycin-resistant enterococci (VRE) in broilers. Eighty-two VRE isolates were recovered from poultry fecal samples between 2000 and mid-2001.

Phenotypic and molecular characterization of community occurring, Western Samoan phage pattern methicillin-resistant Staphylococcus aureus.

In New Zealand, it is estimated that greater than half of the methicillin-resistant Staphylococcus aureus (MRSA) strains recovered from patients belong to what has been termed Western Samoan phage pattern types 1 and 2 (WSPP1, WSPP2). These strains differ from classical MRSA isolates in terms of their lack of multiresistance and community occurrence, suggesting that such strains possess properties and/or characteristics different from those of other MRSA. To address this hypothesis, 10 WSPP1 and WSPP2 isolates from Western Samoa, New Zealand and Australia were compared with common hospital MRSA isolates.

A novel haem compound accumulated in Escherichia coli overexpressing the cydDC operon, encoding an ABC-type transporter required for cytochrome assembly.

cydDC genes encode a heterodimeric ABC transporter required for assembly of the membrane-bound cytochrome bd quinol oxidase and periplasmic cytochromes. Here, we demonstrate that overexpression of functional cydDC genes on a multicopy plasmid results in elevated levels of cytochromes b and d, but most notably formation in anaerobically grown cells of a novel haem-containing component P-574. The pigment has a distinctive absorbance at 574-579 nm and 448 nm in reduced minus oxidised spectra and renders over-producing cells reddish in colour.

Intracellular pH regulation by Mycobacterium smegmatis and Mycobacterium bovis BCG.

Mycobacteria are likely to encounter acidic pH in the environments they inhabit; however intracellular pH homeostasis has not been investigated in these bacteria. In this study, Mycobacterium smegmatis and Mycobacterium bovis [Bacille Calmette--Guérin (BCG)] were used as examples of fast- and slow-growing mycobacteria, respectively, to study biochemical and physiological responses to acidic pH. M.

Oxidase and periplasmic cytochrome assembly in Escherichia coli K-12: CydDC and CcmAB are not required for haem-membrane association.

The mechanism(s) that bacteria use to transport haem into and across the cytoplasmic membrane to complete the assembly of periplasmic cytochromes is unknown. The authors have tested directly the role(s) of two ATP-binding cassette (ABC) transporters - the cydDC and ccmAB gene products - in Escherichia coli by measuring haem uptake in everted (inside-out) membrane vesicles. If haem is exported to the periplasm in vivo, the same process should result in active accumulation in such everted vesicles.

Initial Data for Numerical Relativity.

Initial data are the starting point for any numerical simulation. In the case of numerical relativity, Einstein's equations constrain our choices of these initial data. We will examine several of the formalisms used for specifying Cauchy initial data in the 3 + 1 decomposition of Einstein's equations.