J. Dworkin et Mj. Blaser, NESTED DNA INVERSION AS A PARADIGM OF PROGRAMMED GENE REARRANGEMENT, Proceedings of the National Academy of Sciences of the United Statesof America, 94(3), 1997, pp. 985-990
Programmed gene rearrangements are employed by a variety of microorgan
isms, including viruses, prokaryotes, and simple eukaryotes, to contro
l gene expression. In most instances in which organisms mediate host e
vasion by large families of homologous gene cassettes, the mechanism o
f variation is not thought to involve DNA inversion. Here we report th
at Campylobacter fetus, a pathogenic Gram-negative bacterium, reassert
s a single promoter, controlling surface-layer protein expression, and
one or more complete ORFs strictly by DNA inversion. Rearrangements w
ere independent of the distance between sites of inversion. These rear
rangements permit variation in protein expression from the large surfa
ce-layer protein gene family and suggest an expanding paradigm of prog
rammed DNA rearrangements among microorganisms.