Protein Basics Protein function Protein structure Primary Amino

Protein Basics • Protein function • Protein structure – Primary • Amino acids • Linkage – Secondary – Tertiary – Quaternary • Effect of DNA Mutation

Protein Function in Cell 1. Enzymes • Catalyze biological reactions 2. Structural role • • • Cell wall Cell membrane Cytoplasm

A. Bio-molecules are the basis of traits DNA RNA Protein Trait • Traits represent organisms': - Structure - Function • Proteins determine structure and function • DNA codes for proteins that convey traits

Frank Lloyd Wright

Levels of Protein Structure The Shape it takes depends on the order of the Amino Acids

From our last set of notes: Translation • Second stage of protein production • m. RNA is on a ribosome

Primary structure = order of amino acids in the protein chain

Membrane proteins have adapted to hydrophobic environments

Secondary structure = local folding of residues into regular patterns

Tertiary structure = global folding of a protein chain

Tertiary structures are quite varied

Quaternary structure = Higher-order assembly of proteins

Example of quaternary structure Sir 1/Orc 1 heterodimer Example is Sir 1/Orc 1 complex solved at UW: Hou, Bernstein, Fox, and Keck (2005) Proc. Natl. Acad. Sci. 102, 8489 -94.

Ex: Quaternary structures – You don’t need to memorize these types Tetramer SSB Allows coordinated DNA binding of an Hexamer DNA helicase Allows coordinated DNA binding and ATP hydrolysis Filament Recombinase Allows complete coverage extended molecule

Protein: The Machinery of Life NH 2 -Val-His-Leu-Thr-Pro-Glu. Lys-Ser-Ala-Val-Thr-Ala-Leu-Trp. Gly-Lys-Val-Asn-Val-Asp-Glu-Val. Gly-Glu-…. . “Life is the mode of existence of proteins, and this mode of existence essentially consists in the constant selfrenewal of the chemical constituents of these substances. ” Friedrich Engles, 1878

DNA Mutation Function • Students know how mutations in the DNA sequence of a gene may or may not affect the expression of the gene or the sequence of amino acids in an encoded protein.