title: Cloning and expression of gene fragments encoding the choline-binding domain of pneumococcal murein hydrolases.
abstract: The cloning in Escherichia coli of the 3' moieties of the lytA and cpl-1 genes is described, coding for the C-terminal regions of the lytic amidase of Streptococcus pneumoniae and the phage Cp-1 lysozyme, respectively. The truncated genes were overexpressed in E. coli and the purified polypeptides showed a great affinity for choline, although they were devoid of cell wall-degrading activity. Biochemical and circular dichroism analyses indicated that these are the domains responsible for the specific recognition of the choline-containing pneumococcal cell walls by the lytic enzymes. The data presented here suggested that these choline-binding domains can function independently of their catalytic domains.
authors.affiliation: Centro de Investigaciones Biológicas, C.S.I.C., Velázquez, Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Sánchez-Puelles
authors.forename: J M
authors.initials: JM
authors.lastname: Sanz
authors.forename: J L
authors.initials: JL
authors.lastname: García
authors.forename: E
authors.initials: E
authors.lastname: García
mesh_terms: D000581:Amidohydrolases / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D002794:Choline / Q000378:metabolism*; D002942:Circular Dichroism; D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D007700:Kinetics; D008969:Molecular Sequence Data; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D011487:Protein Conformation; D015183:Restriction Mapping; D013296:Streptococcus pneumoniae / Q000201:enzymology / Q000235:genetics*
chemical_list: D000581:Amidohydrolases; D009238:N-Acetylmuramoyl-L-alanine Amidase; D002794:Choline