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Atomic-force-microscopy (AFM)-based single-molecule force spectroscopy (SMFS) is a powerful yet accessible means to characterize mechanical properties of biomolecules. Historically, accessibility relies upon the nonspecific adhesion of biomolecules to a surface and a cantilever and, for proteins, the integration of the target protein into a polyprotein. However, this assay results in...

BamA is an essential component of the 尾-barrel assembly machine (BAM) that is responsible for insertion and folding of 尾-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. BamA is an OMP itself, and its 尾-barrel transmembrane domain is thought to catalyze OMP insertion and folding, although the molecular mechanism remains...

The 尾-barrel assembly machine (BAM) mediates the biogenesis of outer membrane proteins (OMPs) in Gram-negative bacteria. BamA, the central BAM subunit composed of a transmembrane 尾-barrel domain linked to five polypeptide transport-associated (POTRA) periplasmic domains, is thought to bind nascent OMPs and undergo conformational cycling to catalyze OMP folding and...

The outer membrane of Gram-negative bacteria is an asymmetric membrane with lipopolysaccharides on the external leaflet and phospholipids on the periplasmic leaflet. This outer membrane contains mainly 尾-barrel transmembrane proteins and lipidated periplasmic proteins (lipoproteins). The multisubunit protein 尾-barrel assembly machine (BAM) catalyzes the insertion and folding of the 尾-barrel...

The 尾-barrel assembly machine (BAM) mediates folding and insertion of integral 尾-barrel outer membrane proteins (OMPs) in Gram-negative bacteria. Of the five BAM subunits, only BamA and BamD are essential for cell viability. Here we present the crystal structure of a fusion between BamA POTRA4-5 and BamD from Rhodothermus marinus...

The 尾-barrel assembly machinery (BAM) mediates folding and insertion of 尾-barrel outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria. BAM is a five-protein complex consisting of the 尾-barrel OMP BamA and lipoproteins BamB, -C, -D, and -E. High resolution structures of all the individual BAM subunits and...

Many pathogenic bacteria utilize the type III secretion system (T3SS) to translocate effector proteins directly into host cells, facilitating colonization. In enterohemmorhagic Escherichia coli (EHEC), a subset of T3SS effectors is essential for suppression of the inflammatory response in hosts, including humans. Identified as a zinc protease that cleaves NF-魏B...

Cationic Antimicrobial Peptides (CAMPs) represent a first line of defense against bacterial colonization. When fighting Gram-negative bacteria, CAMPs initially interact electrostatically with the negatively charged phosphate groups in lipid A and are thought to kill bacteria by disrupting their membrane integrity. However, many human pathogens, including Salmonella and Pseudomonas ,...

Metastatic melanoma is among the most intractable cancers to treat; patients show resistance to therapy and limited survival time. A critical step in the development of metastatic melanoma is the acquisition of invasion and transition from thin to thick tumors on the skin, followed by invasion to lymph nodes. Prior...

The assembly of 尾-barrel Outer Membrane Proteins (OMPs) in the outer membrane is essential for gram-negative bacteria. The process requires the 尾-Barrel Assembly Machine (BAM), a multiprotein complex that, in E. coli, is composed of the OMP BamA and four lipoproteins BamB-E. Whereas BamA and BamD are essential, deletion of...