Identification of two iron-repressed periplasmic proteins in Haemophilus influenzae.
AUTOR(ES)
Harkness, R E
RESUMO
Protein expression by Haemophilus influenzae under iron-limiting growth conditions was examined. The five type b strains and four nontypeable strains studied all expressed a new protein of about 40 kDa when deprived of iron during growth. Most strains also expressed a protein of about 31 kDa under the same growth conditions. Both the 40- and 31-kDa proteins were not expressed by cells grown in iron-replete medium. The 40- and 31-kDa proteins were not expressed in iron-deficient medium to which an excess of ferric nitrate had been added, and therefore it was concluded that their expression was iron regulated. These iron-repressed proteins were localized to the periplasmic space. The amino-terminal sequences of both proteins were determined. The N-terminal sequence of the 40-kDa protein had 81% similarity to the N terminus of Fbp, the major iron-binding protein of Neisseria gonorrhoeae and N. meningitidis. The 31-kDa protein sequence showed no homology with any known protein sequence. As no plasmids were found in the strains, it was concluded that these proteins were chromosomally encoded.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=205877Documentos Relacionados
- Identification of Haemophilus influenzae.
- Iron acquisition by Haemophilus influenzae.
- Identification of two minor subunits in the pilus of Haemophilus influenzae.
- Identification of a locus involved in the utilization of iron by Haemophilus influenzae.
- Laboratory identification of Haemophilus influenzae.
