2ltj

Publication Abstract from PubMed

Streptococcus pneumoniae is a serious human pathogen that presents on its surface numerous proteins involved in the host-bacterium interaction. The carbohydrate-active enzymes are particularly well represented among these surface proteins, and many of these are known virulence factors, highlighting the importance of carbohydrate processing by this pathogen. StrH is a surface-attached exo-beta-d-N-acetylglucosaminidase that cooperates with the sialidase NanA and the beta-galactosidase BgaA to sequentially degrade the nonreducing terminal arms of complex N-linked glycans. This enzyme is a large multi-modular protein that is notable for its tandem N-terminal family GH20 catalytic modules, whose individual X-ray crystal structures were recently reported. StrH also contains C-terminal tandem G5 modules, which are uncharacterized. Here, we report the NMR-determined solution structure of the first G5 module in the tandem, G5-1, which along with the X-ray crystal structures of the GH20 modules was used in conjunction with small-angle X-ray scattering to construct a pseudo-atomic model of full-length StrH. The results reveal a model in which StrH adopts an elongated conformation that may project the catalytic modules away from the surface of the bacterium to a distance of up to ~250A.

Conformational Analysis of StrH, the Surface-Attached exo-beta-d-N-Acetylglucosaminidase from Streptococcus pneumoniae.,Pluvinage B, Chitayat S, Ficko-Blean E, Abbott DW, Kunjachen JM, Grondin J, Spencer HL, Smith SP, Boraston AB J Mol Biol. 2012 Nov 12. pii: S0022-2836(12)00877-7. doi:, 10.1016/j.jmb.2012.11.005. PMID:23154168^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.