U.S. Department of Health and Human Services

Genetics and Biochemistry Branch

Rafael Daniel Camerini-Otero, M.D., Ph.D., Chief

​Research Images

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Outer membrane protein (OMP) biogenesis in Gram-negative bacteria.

Outer membrane protein (OMP) biogenesis in Gram-negative bacteria. OMPs are synthesized in the cytoplasm and transported across the inner membrane through the Sec complex. They are then maintained in an insertion-competent conformation in the periplasm (the space between the inner and outer membranes) by molecular chaperones including Skp and SurA. Subsequently they are targeted in the barrel assembly machinery (Bam) complex, a heterooligomer that catalyzes their insertion into the outer membrane by an unknown mechanism. Although it is unclear if OMPs fold before or after they interact with the Bam complex, they reside in the outer membrane in a “β barrel” (closed cylindrical) conformation.

A graphic which depicts outer membrane protein (O M P) biogenesis in Gram-negative bacteriaEnlarge
Hotspots of genetic rearrangementIn this image, hundredfold magnification of a single sperm precursor cell shows the chromosomes (in green) and the places where these chromosomes are most likely to break apart and re-form, called genetic recombination hotspots (in red). Genetic rearrangements at these hotspots have the potential to shuffle maternal and paternal chromosomes, the end results of which ensure that the genetic information in every sperm cell is unique. Source: Fatima Smagulova, Ph.D., USU, and Kevin Brick, Ph.D., NIDDK, NIH.Hotspots of genetic rearrangementEnlarge