The beta sheet, (β-sheet) (also β-pleated sheet) is a common motif of the regular protein secondary structure. Beta sheets consist of beta strands (β-strands) connected laterally by at least two or three backbone hydrogen bonds, forming a generally twisted, pleated sheet. A β-strand is a stretch of polypeptide chain typically 3 to 10 amino acids long with backbone in an extended conformation. The majority of β-strands are arranged adjacent to other strands and form an extensive hydrogen bond network with their neighbors in which the N−H groups in the backbone of one strand establish hydrogen bonds with the C=O groups in the backbone of the adjacent strands. In the fully extended β-strand, successive side chains point straight up and straight down in an alternating pattern. Adjacent β-strands in a β-sheet are aligned so that their Cα atoms are adjacent and their side chains point in the same direction. A simple supersecondary protein topology composed of two or more consecutive antiparallel β-strands linked together by hairpin loops is known as beta-meander. The vast majority of β-meander regions in proteins are found packed against other motifs or sections of the polypeptide chain, forming portions of the hydrophobic core that canonically drives formation of the folded structure. In some cases, these regions can be involved in supramolecular oligomerization. Here you have an example of two beta-meanders in the interface of a protein-protein dimer observed in the structure of the Medicago truncatula Nodulin 13 (PDB code: 7QB6)
#molecularart ... #immolecular ... #betasheet ... #betastrand ... #meander ... #dimerization ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #betasheet ... #betastrand ... #meander ... #dimerization ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
