- 作者: Yen-Chi Yu; Ching-Nan Lin; Shao-Hung Wang; Swee-Chuan Ng; Wensi S Hu; Wan-Jr Syu
- 作者服務機構: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, R. O. C.
- 中文摘要: --
- 英文摘要:
Open reading frame l0045 in the pathogenic island of enterohemorrhagic Escherichia
coli O157:H7 has been predicted to encode a lytic transglycosylase that is
homologous to two different gene products encoded by the same bacteria at loci away
from the island. To deduce the necessity of the presence in the island, we created an
l0045-deleted strain of EHEC and observed that both the level of cytosolic EspA and
that of the other type III secreted proteins in the media were affected. In a
complementation assay, a low level-expressing L0045 appeared to recover efficiently
the type III secretion (TTS). On the other hand, when l0045 was driven to express
robustly, the intracellular levels of representative TTS proteins were severely
suppressed. This suppression is apparently caused by the protein of L0045 per se
since introducing an early translational termination codon abolished the suppression.
Intriguingly, the authentic L0045 was hardly detected in all lysates of EHEC
differently prepared while the same construct was expectedly expressed in the K-12
strain. A unique network must exist in EHEC to tightly regulate the presence of L0045,
and we found that a LEE regulator (GrlA) is critically involved in this regulation. - 中文關鍵字: --
- 英文關鍵字: --