15 research outputs found
Biogenesis and functions of bacterial S-layers.
The outer surface of many archaea and bacteria is coated with a proteinaceous surface layer (known as an S-layer), which is formed by the self-assembly of monomeric proteins into a regularly spaced, two-dimensional array. Bacteria possess dedicated pathways for the secretion and anchoring of the S-layer to the cell wall, and some Gram-positive species have large S-layer-associated gene families. S-layers have important roles in growth and survival, and their many functions include the maintenance of cell integrity, enzyme display and, in pathogens and commensals, interaction with the host and its immune system. In this Review, we discuss our current knowledge of S-layer and related proteins, including their structures, mechanisms of secretion and anchoring and their diverse functions
Measurement of polarization amplitudes and CP asymmetries in B-0 -> phi K*(892)(0)
An angular analysis of the decay B (0) -> phi K (*)(892)(0) is reported based on a pp collision data sample, corresponding to an integrated luminosity of 1.0 fb(-1), collected at a centre-of-mass energy of root S = 7 TeV with the LHCb detector. The P-wave amplitudes and phases are measured with a greater precision than by previous experiments, and confirm about equal amounts of longitudinal and transverse polarization. The S-wave K+ pi(-) and K+ K- contributions are taken into account and found to be significant. A comparison of the B (0) -> phi K (*)(892)(0) and results shows no evidence for direct CP violation in the rate asymmetry, in the triple-product asymmetries or in the polarization amplitudes and phases
Measurement of the phase difference between short- and long-distance amplitudes in the decay
A measurement of the phase difference between the short- and long-distance
contributions to the decay is performed by
analysing the dimuon mass distribution. The analysis is based on collision
data corresponding to an integrated luminosity of 3 collected by
the LHCb experiment in 2011 and 2012. The long-distance contribution to the
decay is modelled as a sum of relativistic
Breit--Wigner amplitudes representing different vector meson resonances
decaying to muon pairs, each with their own magnitude and phase. The measured
phases of the and resonances are such that the interference
with the short-distance component in dimuon mass regions far from their pole
masses is small. In addition, constraints are placed on the Wilson
coefficients, and , and the branching
fraction of the short-distance component is measured.Comment: 23 pages, 4 figures, published in EPJC. All figures and tables, along
with any supplementary material and additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-045.htm
Thiouracil SecA inhibitors: bypassing the effects of efflux pumps and attenuating virulence factor secretion in MRSA and Bacillus anthracis
The CodY-dependent clhAB2 operon is involved in cell shape, chaining and autolysis in Bacillus cereus ATCC 14579
Long-term in situ permafrost thaw effects on bacterial communities and potential aerobic respiration
The decomposition of large stocks of soil organic carbon in thawing permafrost might depend on more than climate change-induced temperature increases: indirect effects of thawing via altered bacterial community structure (BCS) or rooting patterns are largely unexplored. We used a 10-year in situ permafrost thaw experiment and aerobic incubations to investigate alterations in BCS and potential respiration at different depths, and the extent to which they are related with each other and with root density. Active layer and permafrost BCS strongly differed, and the BCS in formerly frozen soils (below the natural thawfront) converged under induced deep thaw to strongly resemble the active layer BCS, possibly as a result of colonization by overlying microorganisms. Overall, respiration rates decreased with depth and soils showed lower potential respiration when subjected to deeper thaw, which we attributed to gradual labile carbon pool depletion. Despite deeper rooting under induced deep thaw, root density measurements did not improve soil chemistry-based models of potential respiration. However, BCS explained an additional unique portion of variation in respiration, particularly when accounting for differences in organic matter content. Our results suggest that by measuring bacterial community composition, we can improve both our understanding and the modeling of the permafrost carbon feedback.A correction to this article has been published. DOI: 10.1038/s41396-019-0384-1</p