TY - JOUR T1 - Does a backwardly read protein sequence have a unique native state? JF - Protein Engineering Y1 - 1996 A1 - Krzysztof A. Olszewski A1 - Andrzej KoliƄski A1 - Jeffrey Skolnick KW - Amino Acid Sequence KW - Computer Simulation KW - Models KW - Molecular KW - Molecular Sequence Data KW - Monte Carlo Method KW - Protein Conformation KW - Protein Engineering KW - Protein Folding KW - Protein Structure KW - Secondary KW - Staphylococcal Protein A KW - Staphylococcal Protein A: chemistry KW - Tertiary AB - Amino acid sequences of native proteins are generally not palindromic. Nevertheless, the protein molecule obtained as a result of reading the sequence backwards, i.e. a retro-protein, obviously has the same amino acid composition and the same hydrophobicity profile as the native sequence. The important questions which arise in the context of retro-proteins are: does a retro-protein fold to a well defined native-like structure as natural proteins do and, if the answer is positive, does a retro-protein fold to a structure similar to the native conformation of the original protein? In this work, the fold of retro-protein A, originated from the retro-sequence of the B domain of Staphylococcal protein A, was studied. As a result of lattice model simulations, it is conjectured that the retro-protein A also forms a three-helix bundle structure in solution. It is also predicted that the topology of the retro-protein A three-helix bundle is that of the native protein A, rather than that corresponding to the mirror image of native protein A. Secondary structure elements in the retro-protein do not exactly match their counterparts in the original protein structure; however, the amino acid side chain contract pattern of the hydrophobic core is partly conserved. VL - 9 UR - http://www.ncbi.nlm.nih.gov/pubmed/9053902 ER -