GH1-family 6-P-β-glucosidases from human microbiome lactic acid bacteria

The crystal structures of two 6-P-β-glucosidases from the GH1 family were determined in the apo form and in the presence of a 6′-P-salicin substrate, of the reaction product 6-P-β-glucose and of glucose corresponding to the aglycon molecule. The presence of natural ligands enabled the definition of the structural elements responsible for the recognition and hydrolysis of 6′-P-β-glucosides.

Domain-level rocking motion within a polymerase that translocates on single-stranded nucleic acid

An X-ray crystallographic structure is described for unliganded Vaccinia virus poly(A) polymerase monomer (VP55), showing the first domain-level structural isoforms among either VP55, it's processivity factor VP39, or the VP55-VP39 heterodimer. The occurrence of domain-level motion specifically in monomeric VP55 is consistent with the finding that the monomeric protein undergoes saltatory translocation whereas the heterodimer does not.

The N-terminal substrate-recognition domain of a LonC protease exhibits structural and functional similarity to cytosolic chaperones

The crystal structure of the intact substrate-recognition domain of a LonC protease shows a large helical hairpin extension (HHE). The HHEs form a basket-like structure on top of the degradation chamber of the LonC protease. The HHE of LonC shares structural and functional similarity to the α-helical tentacle of the periplasmic chaperone Skp.