Disease relevance of pnp

• Thus, as is the case in Escherichia coli, the read-through transcript from rpsO-pnp is cleaved by RNase IIIS in S. coelicolor [1].
• The absB gene encodes a double strand-specific endoribonuclease that cleaves the read-through transcript of the rpsO-pnp operon in Streptomyces coelicolor [1].
• The hypersensitivity due to the insertion was only partially complemented by a cloned pnp gene [2].

High impact information on pnp

• Some of the transcripts of the pnp gene terminate just after the stem of the terminator t2 visible in the nucleotide sequence [3].
• Translation of pnp is initiated by 5'-UUG-3' codon separated by 7 nucleotides from a good ribosome binding site [3].
• Here, we show that the half-lives of both the pnp and rne transcripts are dependent on the intracellular level of polyadenylated transcripts [4].
• This difference is striking, as both mRNAs are greatly stabilized upon the shift to 15 degrees C. However, unlike the lacZ(+) mRNA, which remains stable during adaptation, pnp mRNA decay accelerates [5].
• The bulk of induction results from reversal of autoregulation at a step subsequent to RNase III cleavage of the pnp leader [5].

Biological context of pnp

• The pnp gene is located at 69 min on the Escherichia coli chromosome adjacent to the rpsO gene which encodes the ribosomal protein S15 [3].
• The results suggest that each gene has its own promotor, but that there is coexpression of rpsO and pnp [6].
• Two in-phase gene fusions between pnp and lacZ were constructed [7].
• Furthermore, the S. antibioticus rpsO-pnp intergenic region contains two open reading frames [8].
• The fusions define the translational reading frame of the pnp gene and indicate that the expression of pnp is independent of the upstream rpsO gene [7].

Analytical, diagnostic and therapeutic context of pnp

• Restriction mapping of the positions of the Tn5 insertions and analysis of plasmid-encoded polypeptides in UV-irradiated maxi-cells indicated that the pnp gene is oriented in the counterclockwise direction on the bacterial chromosome [9].

References