A. Laio and C. Micheletti
Are structural biases at protein termini a signature of vectorial folding?
Preprint full text (q-bio archive).
Link to online article.
Experimental investigations of the biosynthesis of a number of
proteins have pointed out that part of the native structure can be
acquired already during translation. We carried out a comprehensive
statistical analysis of some average structural properties of proteins
that have been put forward as possible signatures of this progressive
buildup process. Contrary to a widespread belief, it is found that
there is no major propensity of the amino acids to form contacts with
residues that are closer to the N terminus. Moreover, it is found that
the C terminus is significantly more compact and locally-organized
than the N one. Also this bias, though, is unlikely to be related to
vectorial effects, since it correlates with subtle differences in the
primary sequence. These findings indicate that even if proteins aquire
their structure vectorially no signature of this seems to be
detectable in their average structural properties.