PTH134

PTH134 is a fictional gene designation used in educational and illustrative genome annotation exercises to demonstrate common annotation challenges. The label PTH134 is often presented as a locus tag in simulated bacterial genomes to identify a small protein-coding gene.

In the hypothetical genome, PTH134 encodes a protein of about 210 amino acids, with an estimated molecular weight near 23 kDa. The protein is predicted to be cytosolic and lacks a classical signal peptide or transmembrane segments.

Domain predictions place a helix-turn-helix DNA-binding motif in the N-terminal region, consistent with a potential role as a transcription regulator. The C-terminal portion is inferred to be more flexible and may mediate interactions with other regulatory proteins.

Based on gene neighborhood and domain content, PTH134 is proposed to regulate a small operon associated with oxidative stress response in this fictional context. In silico expression simulations suggest modest upregulation under oxidative or redox-related conditions.

Homology analyses indicate only weak similarity to known XRE-like transcription factors, and there are no close homologs in current curated databases. As a result, the functional assignment remains putative and dependent on future experimental validation.

PTH134 is used to illustrate the limitations of automated annotation, such as reliance on domain predictions and genomic context, and to emphasize the need for experimental data.