title: Streptococcus pneumoniae secretes a glyceraldehyde-3-phosphate dehydrogenase, which binds haemoglobin and haem.
abstract: Streptococcus pneumoniae is a gram positive encapsulated bacterium responsible of septicaemia and upper respiratory infections in children. This pathogen requires iron to survive in the host, which it can obtain of haemoglobin (Hb) or haem. Only two Hb-binding membrane proteins have been identified up to now. However it is unknown whether this pathogen secretes proteins in order to scavenge iron from the Hb or haem. Therefore, in order to explore these possibilities, cellular growth of S. pneumoniae was tested with several alternative iron supplies. The bacterial growth was supported with iron, Hb and haem. Additionally, S. pneumoniae expressed and secreted a protein of 38 kDa which was purified and characterized as Hb and haem-binding protein. This protein was also identified by mass spectrometry as glyceraldehyde-3-phosphate dehydrogenase. Our overall results suggest that S. pneumoniae secretes a protein capable of binding two usefull iron sources for this bacterium (Hb and haem). This protein could be playing a dynamic role in the success of the invasive and infective processes of this pathogen.
authors.affiliation: Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo 290, Del Valle, C.P. 03100, Ciudad de México, D.F., México.
authors.forename: Zelene Edith
authors.initials: ZE
authors.lastname: Vázquez-Zamorano
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: González-López
authors.forename: María Elena
authors.initials: ME
authors.lastname: Romero-Espejel
authors.forename: Elisa Irene
authors.initials: EI
authors.lastname: Azuara-Liceaga
authors.forename: Mavil
authors.initials: M
authors.lastname: López-Casamichana
authors.forename: José de Jesús
authors.initials: Jde J
authors.lastname: Olivares-Trejo
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry / Q000378:metabolism*; D006418:Heme / Q000737:chemistry*; D006454:Hemoglobins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D013296:Streptococcus pneumoniae / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D006454:Hemoglobins; D006418:Heme; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases