Biological membranes are essential structuring components of all living cells. The core elements of membranes are lipid bilayers and integral and peripheral proteins. While a lipid bilayer constitutes the hydrophobic barrier of a membrane and prevents the arbitrary exchange of solutes, transmembrane proteins (TMPs)a allow the regulated exchange of solutes across the lipid bilayer or they transduce signals from one side of the membrane to the other. Many membrane proteins perform enzymatic reactions, which take place at the membrane–water interface. Specific lipid–protein interactions are important for the stable integration and activity of integral and peripheral membrane proteins. TMPs can be subdivided into two classes according to their transmembrane (TM) structure, namely α-helical TMPs and TMPs with β-sheet secondary structure in the lipid bilayer. While TMPs with a single TM helix are common, all TMPs with β-sheet secondary structure known to date form closed β-barrels with at least 8 antiparallel TM β-strands. In these β-barrels, all β-strands are connected to their next neighbors through hydrogen bonds between the amide-protons and the carbonyl groups of the polypeptide backbone. The β-barrel structure is closed through hydrogen bonds formed between the amino-terminal and the carboxy-terminal membrane-spanning β-strands. In bacteria, membrane chaperones as the BamABCDE complex, are essential for helping the proper folding of beta barrels. Here you have a morphing transition showing how the BamABCDE complex helps to fold a beta barrel protein (yellow ribbons) (PDB codes: 7TT5, 7TT6 and 7TT7)
#molecularart ... #immolecular .. #folding ... #chaperone ... #BamABCDE ... #membrane ... #betabarrel ... #cryoem
Morphing transition rendered and animated with @USCFChimeraX
#molecularart ... #immolecular .. #folding ... #chaperone ... #BamABCDE ... #membrane ... #betabarrel ... #cryoem
Morphing transition rendered and animated with @USCFChimeraX
