BCH 2333 Lecture Notes - Lecture 8: Hydrophile, Coiled Coil, Ribbon Diagram
16 Dec 2017
School
Department
Course
Professor
Document Summary
Combination of secondary structure elements ( -helixes, sheets, turns, or loops) Often repeated in the same protein and/or different proteins. 4 very common motifs: motif, -hairpin, greek key, . Gets called helix-loop-helix motif as the turn gets longer: 12 or more residue turn. When the helixes align, there is usually a hydrophobic interaction that helps bring the helixes together. Coiled coil: two helixes coil around each other. Interface between helixes is hydrophobic, around the outsides of the helix is hydrophilic. Salt bridges surround hydrophobic faces to help protect the hydrophobic interactions. 2 antiparallel strands connected by a loop. Bends a hairpin in the middle, giving all 4 strands an antiparallel fashion in plan together. H bonding between all antiparallel strands, very stable sheet core. Sheet is parallel - bent h bonds, less stable. Helix is important to stabilize structure and the make up for the bent h bonds. Hydrophobic residues on -helix interface with hydrophobic residues of sheets.
