1llh
From Proteopedia
ARE CARBOXY TERMINII OF HELICES CODED BY THE LOCAL SEQUENCE OR BY TERTIARY STRUCTURE CONTACTS
Overview
alpha-helices within proteins are often terminated (capped) by distinctive configurations of the polypeptide chain. Two common arrangements are the Schellman motif and the alternative alpha(L) motif. Rose and coworkers developed stereochemical rules to identify the locations of such motifs in proteins of unknown structure based only on their amino acid sequences. To check the effectiveness of these rules, they made specific predictions regarding the structural and thermodynamic consequences of certain mutations in T4 lysozyme. We have constructed these mutants and show here that they have neither the structure nor the stability that was predicted. The results show the complexity of the protein-folding problem. Comparison of known protein structures may show that a characteristic sequence of amino acids (a sequence motif) corresponds to a conserved structural motif. In any particular protein, however, changes in other parts of the sequence may result in a different conformation. The structure is determined by sequence as a whole, not by parts considered in isolation.
About this Structure
1LLH is a Single protein structure of sequence from Enterobacteria phage t4. This structure supersedes the now removed PDB entry 1joz. Full crystallographic information is available from OCA.
Reference
A test of proposed rules for helix capping: implications for protein design., Sagermann M, Martensson LG, Baase WA, Matthews BW, Protein Sci. 2002 Mar;11(3):516-21. PMID:11847274 Page seeded by OCA on Sat May 3 00:02:13 2008
