Haem acquisition is facilitated by a novel receptor Hma and required by uropathogenic Escherichia coli for kidney infection (Mol Microbiol, 2009, 71:79-91)

報告日期: 2009/03/24
報告時間: 17:10/18:00
報告學生: 陳俊良
講評老師: 吳俊忠
附件下載:

http://basicmed.med.ncku.edu.tw/admin/up_img/980324-3.pdf

Haem acquisition is facilitated by a novel receptor Hma

and required by uropathogenic Escherichia coli for kidney infection

Molecular Microbiology (2009) 71(1): 79–91

 

Time: 2009/3/24 17:10-18:00

Place: Room 602

Speaker: 陳俊良

Commentator: 吳俊忠 老師

 

Abstract:

       Uropathogenic Escherichia coli (UPEC) is the most common etiological agent of community-acquired urinary tract infections (UTIs) and accounts for 80% of these infections. A number of virulence determinants including the highly specialized iron acquisition systems facilitate the ability of UPEC to colonize the urinary tract and exert cytopathic effects. Both the heam receptor, ChuA, and TonB-dependent iron transport system have been shown to facilitate UPEC to acquire the limited free iron within the mammalian host during infection. Recently, a novel putative iron receptor, Hma, was identified as an antigenic outer membrane protein in UPEC strain CFT073. Expression of Hma was induced under iron limitation or growth in human urine. A putative Fur box was identified in the promoter region of hma, and a putative TonB box was found in the N-terminal region of Hma1. Based on this finding, the authors further isolated and characterized a hma deletion mutant of strain CFT073 and an E. coli K12 strain that expressed Hma with 6xHis-tag. They demonstrated that Hma is a heamin-binding protein with high affinity, and the function of Hma depended on TonB but not ChuA. They further identified that Tyr-126, although not essential for heam binding, is a key residue for the function of Hma. Finally, they showed that both Hma and ChuA contribute to the maximum kidney colonization of UPEC2.

 

Reference:

1.         Hagan E.C. and Mobley H.L., (2007) Uropathogenic Escherichia coli outer membrane antigens expressed during urinary tract infection., Infect. Immun., 75(8): 39413949.

2.         Hagan E.C. and Mobley H.L., (2009) Haem acquisition is facilitated by a novel receptor Hma and required by uropathogenic Escherichia coli for kidney infection., Mol Microbiol., 71(1):79-91.