Abstract :
[en] In the present study, an extensive analysis of the aromatic Tyr-X interactions is
performed on a data set of 593 PDB structures, X being Phe, His, Tyr, and Trp.
The nonredundant Tyr-X pairs (2645) were retained and separated by both the
residue distance in the sequence and the secondary structures they bridge.
Similar to the Phe-X and His-X pairs, the far-sequence Tyr-X pairs (X partner >
five apart in the sequence: 74%) show comparable secondary structures and
conformers for either type of X partner, in contrast with the near-sequence Tyr-X
pairs (26%). As the Phe-X pairs, the near-sequence Tyr-X pairs stabilize
secondary structures, mainly the alpha- helices (positions 1, 3, and 4) and the
beta-strands (position 2). Like the Phe-X and His-X pairs, most far-sequence
Tyr-X pairs (34%) bridge beta-strands and only 11% bridge helices. As for the
Phe-X and the His-X pairs, the X partners of the far-sequence Tyr-X pairs are
frequently "above" the tyrosine ring with tilted and normal rings, whereas the X
partner of the near-sequence Tyr-X pairs gradually moves from the "aside" to the
"above" location, together with a progressive decrease of normal and increase of
parallel rings, respectively. Unlike the His-X pairs, the interactions of the
hetroatom in Tyr-X pairs are only favored with a sequence position +4 and over,
owing to the spatial accessibility of the heteroatom.
Scopus citations®
without self-citations
17