Characterization of major surface protease homologues of Trypanosoma congolense.

Trypanosomes encode a family of proteins known as Major Surface Metalloproteases (MSPs). We have identified six putative MSPs encoded within the partially sequenced T. congolense genome.

Bacteriophage lambda repressor allelic modulation of the Rex exclusion phenotype.

The sensitivity of delta red-gam delta ren mutants of bacteriophage lambda to Rex exclusion by lambda rexA+ rexB+ lysogens is modulated by the prophage cI repressor allele. We show the following: (i) lambda spi156 delta nin5 forms plaques on a cI+-rexA+-rexB+ lysogen with 10(5)-fold higher efficiency than on cI[Ts]-rexA+-rexB+ derivatives. (ii) The cI[Ts]857 allele augmentation of Rex exclusion is recessive to cI+.