N-terminus of mature heat-labile enterotoxin chain B is critical for its extracellular secretion in Vibrio cholerae.
The effects of addition of a few amino acids to the amino- and carboxy-terminal regions of the mature portion of the heat-labile enterotoxin chain B (LTB) of Escherichia coli on protein export, secretion and assembly were investigated. In E. coli, LTB (secretory protein) with or without the extension at the N- or C-terminus accumulated in the periplasmic fraction. For Vibrio cholerae, LTB with the extension at the C-terminus was exported to the periplasm followed by secretion to the extracellular milieu. However, LTB with the N-terminus extension was exported to the periplasm only. Our findings suggest that in the case of V. cholerae, the N-terminus of the mature LTB plays an important role in its secretion to the extracellular milieu.
Mukhija
R
R
Gene Regulation Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India.
Garg
L C
LC
D000596:Amino Acids / Q000737:chemistry; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D004768:Enterotoxins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins; D015870:Gene Expression; D008969:Molecular Sequence Data; D019897:Periplasm / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D014734:Vibrio cholerae / Q000235:genetics / Q000378:metabolism*
D000596:Amino Acids; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D011956:Receptors, Cell Surface; C034993:ganglioside receptor; C027538:heat-labile enterotoxin, E coli