Structural basis of sialidase in complex with geranylated flavonoids as potent natural inhibitors

The crystal structure of sialidase from C. perfringens, a pathogenic bacterium causing various gastrointestinal diseases, was determined in complex with a potent natural polyphenolic geranylated flavonoid-based inhibitor. The complex structure and comparative kinetic studies revealed that the geranyl group and C3' hydroxyl group of the flavonoid backbone contribute to inhibition of the bacterial sialidase and generation of the stable enzyme-inhibitor complex.

Structures of inactive CRP species reveal the atomic details of the allosteric transition that discriminates cyclic nucleotide second messengers

Binding of cAMP and cGMP to the global transcription factor CRP results in different allosteric transitions of the protein. cGMP binding induces an inhibitory conformational change of CRP.