TRASH, a novel metal binding domain predicted to be involved in heavy metal sensing, trafficking and resistance

We describe a previously undetected domain – TRASH – containing a well-conserved cysteine motif that we anticipate to be involved in metal coordination. TRASH is encoded by multiple prokaryotic genomes and is present in transcriptional regulators, cation-transporting ATPases and hydrogenases, and is also present as a stand-alone module. The observed domain associations and conserved genome context of TRASH-encoding genes in prokaryotic genomes suggest that TRASH constitutes a novel component in metal trafficking and heavy-metal resistance. The role of the multiple copies of TRASH that are present in vertebrate proteins remains to be elucidated.