Pneumocystis murina MSG gene family and the structure of the locus associated with its transcription.

Analysis of the Pneumocystis murina MSG gene family and expression-site locus showed that, as in Pneumocystis carinii, P. murina MSG genes are arranged in head-to-tail tandem arrays located on multiple chromosomes, and that a variety of MSG genes can reside at the unique P. murina expression site. Located between the P. murina expression site and attached MSG gene is a block of 132 basepairs that is also present at the beginning of MSG genes that are not at the expression site. The center of this sequence block resembles the 28 basepair CRJE of P. carinii, but the block of conserved sequence in P. murina is nearly five times longer than in P. carinii, and much shorter than in P. wakefieldiae. These data indicate that the P. murina expression-site locus has a distinct structure.