View source for 109l

[[Image:109l.jpg|left|200px]]

 {{Structure
|PDB= 109l |SIZE=350|CAPTION= <scene name='initialview01'>109l</scene>, resolution 1.85&Aring;
|SITE= 
|LIGAND= <scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>
|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Lysozyme Lysozyme], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.17 3.2.1.17] </span>
|GENE= 
|DOMAIN=
|RELATEDENTRY=
|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=109l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=109l OCA], [http://www.ebi.ac.uk/pdbsum/109l PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=109l RCSB]</span>
}}

'''STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME'''


==Overview==
The propensity of an amino acid to form an alpha helix in a protein was determined by multiple amino substitutions at positions 44 and 131 in T4 lysozyme. These positions are solvent-exposed sites within the alpha helices that comprise, respectively, residues 39 to 50 and 126 to 134. Except for two acidic substitutions that may be involved in salt bridges, the changes in stability at the two sites agree well. The stability values also agree with those observed for corresponding amino acid substitutions in some model peptides. Thus, helix propensity values derived from model peptides can be applicable to proteins. Among the 20 naturally occurring amino acids, proline, glycine, and alanine each have a structurally unique feature that helps to explain their low or high helix propensities. For the remaining 17 amino acids, it appears that the side chain hydrophobic surface buried against the side of the helix contributes substantially to alpha helix propensity.

==About this Structure==
109L is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=109L OCA]. 

==Reference==
Structural basis of amino acid alpha helix propensity., Blaber M, Zhang XJ, Matthews BW, Science. 1993 Jun 11;260(5114):1637-40. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8503008 8503008]
[[Category: Enterobacteria phage t4]]
[[Category: Lysozyme]]
[[Category: Single protein]]
[[Category: Blaber, M.]]
[[Category: Matthews, B W.]]
[[Category: hydrolase(o-glycosyl)]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 18:26:38 2008''