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Structural characterization of the Streptococcus pneumoniae carbohydrate substrate‐binding protein SP0092
Author(s) -
Culurgioni Simone,
Tang Minzhe,
Walsh Martin Austin
Publication year - 2017
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x16020252
Subject(s) - streptococcus pneumoniae , dimer , carbohydrate , ligand (biochemistry) , chemistry , monomer , substrate (aquarium) , biochemistry , stereochemistry , biology , receptor , organic chemistry , ecology , polymer , antibiotics
Streptococcus pneumoniae is an opportunistic respiratory pathogen that remains a major cause of morbidity and mortality globally, with infants and the elderly at the highest risk. S. pneumoniae relies entirely on carbohydrates as a source of carbon and dedicates a third of all uptake systems to carbohydrate import. The structure of the carbohydrate‐free substrate‐binding protein SP0092 at 1.61 Å resolution reveals it to belong to the newly proposed subclass G of substrate‐binding proteins, with a ligand‐binding pocket that is large enough to accommodate complex oligosaccharides. SP0092 is a dimer in solution and the crystal structure reveals a domain‐swapped dimer with the monomer subunits in a closed conformation but in the absence of carbohydrate ligand. This closed conformation may be induced by dimer formation and could be used as a mechanism to regulate carbohydrate uptake.