biostudies-literatureDrabinska JNational Science Center Poland9833https://www.ebi.ac.uk/biostudies/studies/S-EPMC8466066biostudies-literatureUnknown22(18)For nearly half of the proteome of an important pathogen, <i>Pseudomonas aeruginosa</i>, the function has not yet been recognised. Here, we characterise one such mysterious protein PA2504, originally isolated by us as a sole partner of the RppH RNA hydrolase involved in transcription regulation of multiple genes. This study aims at elucidating details of PA2504 function and discussing its implications for bacterial biology. We show that PA2504 forms homodimers and is evenly distributed in the cytoplasm of bacterial cells. Molecular modelling identified the presence of a Tudor-like domain in PA2504. Transcriptomic analysis of a <i>ΔPA2504</i> mutant showed that 42 transcripts, mainly coding for proteins involved in sulphur metabolism, were affected by the lack of PA2504. In vivo crosslinkinInternational journal of molecular sciencesSearching for Biological Function of the Mysterious PA2504 Protein from <i>Pseudomonas aeruginosa</i>.PMC8466066UMO-2018/29/N/NZ6/01701Drabinska JSteczkiewicz KKujawa MKraszewska EfalseSearching for Biological Function of the Mysterious PA2504 Protein from <i>Pseudomonas aeruginosa</i>.For nearly half of the proteome of an important pathogen, <i>Pseudomonas aeruginosa</i>, the function has not yet been recognised. Here, we characterise one such mysterious protein PA2504, originally isolated by us as a sole partner of the RppH RNA hydrolase involved in transcription regulation of multiple genes. This study aims at elucidating details of PA2504 function and discussing its implications for bacterial biology. We show that PA2504 forms homodimers and is evenly distributed in the cytoplasm of bacterial cells. Molecular modelling identified the presence of a Tudor-like domain in PA2504. Transcriptomic analysis of a <i>ΔPA2504</i> mutant showed that 42 transcripts, mainly coding for proteins involved in sulphur metabolism, were affected by the lack of PA2504. In vivo crosslinkin2021-01-01T00:00:00Z2021 Sep2026-04-08T06:55:33.468Z2022-02-11T11:41:02.891ZS-EPMC84660663457599610.3390/ijms22189833