The role of the N-terminal amphipathic helix in bacterial YidC: Insights from functional studies, the crystal structure and molecular dynamics simulations.

The evolutionary conserved YidC is a unique dual-function membrane protein that adopts insertase and chaperone conformations. The N-terminal helix of Escherichia coli YidC functions as an uncleaved signal sequence and is important for membrane insertion and interaction with the Sec translocon. Here, we report the first crystal structure of Thermotoga maritima YidC (TmYidC) including the N-terminal amphipathic helix (N-AH) (PDB ID: 6Y86).

Chromatographic clarification overcomes chromatin-mediated hitch-hiking interactions on Protein A capture column.

Protein A capture chromatography is a critical unit operation in the clearance of host cell protein (HCP) impurities in monoclonal antibody (mAb) purification processes. Though one of the most effective purification steps, variable levels of protein impurities are often observed in the eluate. Coelution of HCP impurities is suggested to be strongly affected by the presence of chromatin complexes (Gagnon et al.

Filling the Green Gap of a Megadalton Photosystem I Complex by Conjugation of Organic Dyes.

Photosynthesis is Nature's major process for converting solar into chemical energy. One of the key players in this process is the multiprotein complex photosystem I (PSI) that through absorption of incident photons enables electron transfer, which makes this protein attractive for applications in bioinspired photoactive hybrid materials. However, the efficiency of PSI is still limited by its poor absorption in the green part of the solar spectrum.

Solid-state biophotovoltaic cells containing photosystem I.

The large multiprotein complex, photosystem I (PSI), which is at the heart of light-dependent reactions in photosynthesis, is integrated as the active component in a solid-state organic photovoltaic cell. These experiments demonstrate that photoactive megadalton protein complexes are compatible with solution processing of organic-semiconductor materials and operate in a dry non-natural environment that is very different from the biological membrane.

The YidC/Oxa1/Alb3 protein family: common principles and distinct features.

The members of the YidC/Oxa1/Alb3 protein family are evolutionary conserved in all three domains of life. They facilitate the insertion of membrane proteins into bacterial, mitochondrial, and thylakoid membranes and have been implicated in membrane protein folding and complex formation. The major classes of substrates are small hydrophobic subunits of large energy-transducing complexes involved in respiration and light capturing.

Bacillus subtilis YqjG is required for genetic competence development.

Members of the evolutionary conserved Oxa1/Alb3/YidC family have been shown to play an important role in membrane protein insertion, folding and/or assembly. Bacillus subtilis contains two YidC-like proteins, denoted as SpoIIIJ and YqjG. SpoIIIJ and YqjG are largely exchangeable, but SpoIIIJ is essential for spore formation and YqjG cannot complement this activity.

Inactivation of the Ecs ABC transporter of Staphylococcus aureus attenuates virulence by altering composition and function of bacterial wall.

Background: Ecs is an ATP-binding cassette (ABC) transporter present in aerobic and facultative anaerobic gram-positive Firmicutes. Inactivation of Bacillus subtilis Ecs causes pleiotropic changes in the bacterial phenotype including inhibition of intramembrane proteolysis. The molecule(s) transported by Ecs is (are) still unknown.

Bacillus subtilis SpoIIIJ and YqjG function in membrane protein biogenesis.

In all domains of life Oxa1p-like proteins are involved in membrane protein biogenesis. Bacillus subtilis, a model organism for gram-positive bacteria, contains two Oxa1p homologs: SpoIIIJ and YqjG. These molecules appear to be mutually exchangeable, although SpoIIIJ is specifically required for spore formation.

Insight into the proteome of the hyperthermophilic Crenarchaeon Ignicoccus hospitalis: the major cytosolic and membrane proteins.

Ignicoccus hospitalis, a hyperthermophilic, chemolithoautotrophic Crenarchaeon, is the host of Nanoarchaeum equitans. Together, they form an intimate association, the first among Archaea. Membranes are of fundamental importance for the interaction of I.

Towards the development of Bacillus subtilis as a cell factory for membrane proteins and protein complexes.

Background: The Gram-positive bacterium Bacillus subtilis is an important producer of high quality industrial enzymes and a few eukaryotic proteins. Most of these proteins are secreted into the growth medium, but successful examples of cytoplasmic protein production are also known. Therefore, one may anticipate that the high protein production potential of B.