Primary SecondaryTertiary Quaternary THVLPFEKINEGFDLLRSGESI Tertiary Structure Arrangement of secondary structure within a single polypeptide Quaternary Structure Arrangement of several polypeptides within a protein complex 0 500 1000 1500 New FoldsTotal Folds SCOP Protein Folds 0 25000 50000 75000 100000 Total FoldsTotal Structures Protein Structures Image credits: All molecular structures were created from copyright-free PDB les available at www.pdb.org. The PDB identier of each le, and the original reference, are provided here for scholarly purposes. Alcohol dehydrogenase: PDB ID 1ADC Li H, Hallows WH, Punzi JS, Pankiewicz KW, Watanabe KA, et al. (1994) Crystallographic studies of isosteric NAD analogues bound to alcohol dehydrogenase: specicity and substrate binding in two ternary complexes. Biochemistry 33: 1173411744. Carbonic anhydrase: PDB ID 1CA2 Eriksson AE, Jones TA, Liljas A (1988) Rened structure of human carbonic anhydrase II at 2.0 A resolution. Proteins 4: 274282. doi:10.1002/prot.340040406. Myoglobin: PDB ID 1MBO Phillips SE (1980) Structure and renement of oxymyoglobin at 1.6 A resolution. J Mol Biol 142: 531554. Hemoglobin: PDB ID 2DN1 Park S-Y, Yokoyama T, Shibayama N, Shiro Y, Tame JRH (2006) 1.25 A resolution crystal structures of human haemoglobin in the oxy, deoxy and carbonmonoxy forms. J Mol Biol 360: 690701. doi:10.1016/j.jmb.2006.05.036. Image credits (key appears at end of video) 1PLQ: Krishna TS, Kong XP, Gary S, Burgers PM, Kuriyan J. Crystal structure of the eukaryotic DNA polymerase processivity factor PCNA. Cell(Cambridge,Mass). 1995;79: 12331243. doi:10.1016/0092-8674(94)90014-0 1STD:Lundqvist T, Rice J, Hodge CN, Basarab GS, Pierce J, Lindqvist Y. Crystal structure of scytalone dehydratase--a disease determinant of the rice pathogen, Magnaporthe grisea. Structure. 1994;2: 937944. doi:10.1016/S0969-2126(94)00095-6 4TIM:Noble ME, Verlinde CL, Groendijk H, Kalk KH, Wierenga RK, Hol WG. Crystallographic and molecular modeling studies on trypanosomal triosephosphate isomerase: a critical assessment of the predicted and observed structures of the complex with 2-phosphoglycerate. J Med Chem. 1991;34: 27092718.1TSP:Steinbacher S, Seckler R, Miller S, Steipe B, Huber R, Reinemer P. Crystal structure of P22 tailspike protein: interdigitated subunits in a thermostable trimer. Science. 1994;265: 383386.4BCL:Tronrud DE, Matthews BW. Renement of the Structure of a Water-Soluble Antenna Complex from Green Photosynthetic Bacteria by Incorporation of the Chemically Determined Amino Acid Sequence. Photosynthetic Reaction Center. 1998;1: 13null.2POR:Weiss MS, Schulz GE. Structure of porin rened at 1.8 A resolution. JMolBiol. 1992;227: 493509. doi:10.1016/0022-2836(92)90903-W 1AFC:Zhu X, Hsu BT, Rees DC. Structural studies of the binding of the anti-ulcer drug sucrose octasulfate to acidic broblast growth factor. Structure. 1993;1: 2734. doi:10.1016/0969-2126(93)90006-3 Image credits (key appears at end of video) 1BRS:Buckle AM, Schreiber G, Fersht AR. Protein-protein recognition: crystal structural analysis of a barnase-barstar complex at 2.0-A resolution. Biochemistry. 1994;33: 88788889.2BBK:Chen L, Doi M, Durley RC, Chistoserdov AY, Lidstrom ME, Davidson VL, et al. Rened crystal structure of methylamine dehydrogenase from Paracoccus denitricans at 1.75 A resolution. J Mol Biol. 1998;276: 131149. doi:10.1006/jmbi.1997.1511 1BL8:Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, et al. The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science. 1998;280: 6977. doi:10.1126/science.280.5360.69 2CCY:Finzel BC, Weber PC, Hardman KD, Salemme FR. Structure of ferricytochrome c from Rhodospirillum molischianum at 1.67 A resolution. J Mol Biol. 1985;186: 627643.2HLA:Garrett TP, Saper MA, Bjorkman PJ, Strominger JL, Wiley DC. Specicity pockets for the side chains of peptide antigens in HLA-Aw68. Nature. 1989;342: 692696. doi:10.1038/342692a0 1CCA:Goodin DB, McRee DE. The Asp-His-Fe triad of cytochrome c peroxidase controls the reduction potential, electronic structure, and coupling of the tryptophan free radical to the heme. Biochemistry. 1993;32: 33133324.1MSA:Hester G, Kaku H, Goldstein IJ, Wright CS. Structure of mannose-specic snowdrop (Galanthus nivalis) lectin is representative of a new plant lectin family. NatStructBiol. 1995;2: 472479. doi:10.1038/nsb0695-472 1DFJ:Kobe B, Deisenhofer J. A structural basis of the interactions between leucine-rich repeats and protein ligands. Nature. 1996;374: 183186. doi:10.1038/374183a0 2CCY 1CCA 2BBK 4TIM1BRS 1BL8 1STD 4BCL 1PLQ 1DFJ 2HLA 1TSP 1MSA 2POR 1AFC