FIG. 4.

Northern blot identification of two mRNA transcripts from 20 μg of P. bryantii B₁4 total RNA hybridized to 1,721-bp DNA PCR probes (FW-xynA and RV-xynB) containing fragments of xynA and xynB (residues 3319 to 5040). The size of the 3.5-kb transcript corresponds to the expected size of a single polycistronic transcript comprising the xynA, xynB, and xynD genes. The size of the 5.8-kb transcript corresponds to the expected size of a single transcript comprising the xynA, xynB, xynD, and xynE genes. No hybridization of the xynA-xynB probe was observed when it was used with 20 μg of either mouse liver or Saccharomyces cerevisiae total RNA (data not shown). The sizes of the transcripts were determined by comparison with P. bryantii B₁4 16S and 23S ribosomal DNA.