Clonal Distribution and Phase-Variable Expression of a Major Histocompatibility Complex Analogue Protein in Staphylococcus aureus

Abstract
The mapW gene of Staphylococcus aureus strain N315 contains a poly(A) tract which truncates translation of the protein. This study demonstrates that mapW is an allelic variant of the map/eap genes found in other strains and that the variation in the length of this poly(A) tract suggests that it is a contingency locus.