BIO206H5 Study Guide - Midterm Guide: Tata-Binding Protein, Sigma Factor, Eukaryotic Transcription
Document Summary
Notes for second midterm: folding is important since it reduces the loss of function, prevents diseases which are associated with miss-folded proteins. Helix it is right handed helix stabilized by h bonds between c=o of peptide group n and n- H of peptide group n+4: 3. 6 aa are required for one complete turn. Sheet adjacent chains held together by hydrogen bonds between backbone. Stability depends on the number of hydrogen bonds. Results in formation of either cylinder or barrel shape or flat planar sheets: note that the arrow head points towards the c-terminus, motifs and domain are part of tertiary of structure. Motif: recurring combination of secondary structure in different region of the protein, ex (helix-turn-helix). It is described in secondary structural terms: the helix loop helix is a calcium ion binding motif. It is able to hold calcium ion because it has negatively charged asp, asn, Thr: zinc-finger motif is designed to hold zn ion.
