NMR of hydrogen bonding in cold-shock protein A and an analysis of the influence of crystallographic resolution on comparisons of hydrogen bond lengths.

ABSTRACT: Hydrogen bonding in cold-shock protein A of Escherichia coli has been investigated using long-range HNCO spectroscopy. Nearly half of the amide protons involved in hydrogen bonds in solution show no measurable protection from exchange in water, cautioning against a direct correspondence between hydrogen bonding and hydrogen exchange protection. The N to O atom distance across a hydrogen bond, R(NO), is related to the size of the (3h)J(NC') trans hydrogen bond coupling constant and the amide proton chemical shift. Both NMR parameters show poorer agreement with the 2.0-A resolution X-ray structure of the cold-shock protein studied by NMR than with a 1.2-A resolution X-ray structure of a homologous cold-shock protein from the thermophile B. caldolyticus. The influence of crystallographic reso

SUBMITTER: Alexandrescu AT 

PROVIDER: S-EPMC2253202 | biostudies-literature | 2001 Sep

REPOSITORIES: biostudies-literature