Asparagine, hydrogen-bonding

As a p hydroxy derivative of phenylalanine tyrosine has properties similar to those of phenylalanine plus the ability to engage m hydrogen bonding via its —OH group Asparagine and glutamine are not amines they are amides The side chains of both O... 

The only sequence-specific hydrogen bonds between TBP side chains and the bases in the minor groove occur at the very center of the TATA box (Figure 9.7). The amide groups of two asparagine side chains donate four hydrogen bonds, two each to adjacent bases on the same DNA strand (Asn 69... 

Fig. 6. Ramachandran plots for simulated Ac-Ala-Xaa-Ala-Ala-NMe peptides with Xaa = glutamine or asparagine, with a constrained side chain-to-backbone hydrogen bond. Conformational distribution for glutamine i (A) and for the residue i +1 to which the glutamine is hydrogen-bonded (B). Conformational distribution for asparagine i (C) and for the residue i +1 to which it is hydrogen-bonded (D).

Fig. 54. An asparagine side chain making a hydrogen-bond to the main chain NH of residue n + 2, an arrangement which helps stabilize the central peptide of a tight turn. Residues 91-93 from chymotrypsin.

A specific proposal for the role of the asparagine was developed in a model which breaks the hydrogen bonds to the backbone and rotates the asparagine to-... 

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