103l: Difference between revisions

Studies of extant protein sequences indicate that amino-acid insertions, and deletions are preferentially located in loop regions, which has, traditionally been explained as the result of selection removing, deleterious mutations within secondary structural elements from the, population. But there is no a priori reason to discount the possibility, that insertions within secondary structure could either be tolerated until, compensatory mutations arise, or have effects that are propagated away, from secondary structure into loops. Earlier studies have indicated that, insertions are generally tolerated, although much less well within, secondary structure elements than in loop regions. Here we show that, amino-acid insertions in an alpha-helix of T4 lysozyme can be accepted in, two different ways. In some cases the inserted amino acids are, accommodated within the helix, leading to the translocation of wild-type, residues from the helix to the preceding loop. In other cases the, insertion causes a 'looping-out' in the first or last turn of the helix., The individual structural responses seem to be dominated by the, maintenance of the interface between the helix and the rest of the, protein.

103L is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t2 Enterobacteria phage t2] with CL and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=103L OCA].  

[[Category: Enterobacteria phage t2]]

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 15:49:18 2007''