A nicer side of a bacterial enzyme.Diphtheria diphtheria (dĭfthēr`ēə), acute contagious disease caused by Corynebacterium diphtheriae (Klebs-Loffler bacillus) bacteria that have been infected by a bacteriophage. It begins as a soreness of the throat with fever. , cholera, and pertussis pertussis: see whooping cough. (whooping cough) share a common origin. These diseases are caused by bacteria that secrete enzymes into the cells of animals they infect. The enzymes, known as ADP-ribosyltransferases, modify cellular proteins and in the process cause the symptoms of the diseases. Investigators had assumed that all forms of these enzymes cause disease, but they have now found a bacterium, Vibrio fischeri, that secretes ADP-ribosyltransferases and is nonpathogenic. This bioluminescent bi·o·lu·mi·nes·cence n. Emission of visible light by living organisms such as the firefly and various fish, fungi, and bacteria. bi bacterium forms a symbiotic relationship with squid (SN: 9/14/96, p. 167). V. fischeri makes two forms of ADP-ribosyltransferase, says Karl A. Reich of the Howard Hughes Medical Institute Howard Hughes Medical Institute, (HHMI), nonprofit medical research organization founded in 1953 by Howard Hughes and largly funded from proceeds of the 1984–85 sale of Hughes Aircraft. Headquartered in Chevy Chase, Md. at Stanford University School of Medicine Stanford University School of Medicine is affiliated with Stanford University and is located at Stanford University Medical Center in Stanford, California, adjacent to Palo Alto and Menlo Park. . He and his colleagues are mutating the gene for each form in order to study the roles of the enzymes. Preliminary results from bacteria with one of the genes mutated suggest its enzyme helps the bacteria persist inside the host squid, says Reich. |
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion