The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.
You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.
We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.
We are interested in where in or outside the cell the gene product carries out its function.
We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.
Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.
The evidence gathered here pertains specifically to Pseudomonas putida KT2440 and to the PvdRT–OpmQ tripartite efflux pump implicated in pyoverdine (PVD) secretion/recycling, in which PvdT is the inner-membrane ABC (MacB-like) ATPase/permease component. This matches the UniProt-provided identity context for Q88F88 (pvdT/PP_4210) as a MacB-like ABC transporter subunit involved in pyoverdine export. (stein2023navigatingpyoverdineand pages 29-31, stein2023therndefflux pages 1-2)
Pyoverdine is a high-affinity siderophore used by fluorescent pseudomonads to acquire iron under iron-limiting conditions. After iron capture and uptake, the siderophore can be re-exported for reuse (“recycling”), enabling repeated iron-scavenging cycles. A recent authoritative review summarizes this recycling logic for Pseudomonas pyoverdines, in which the siderophore is not chemically modified during iron release and is directed back to an efflux pump for export. (schalk2025bacterialsiderophoresdiversity pages 46-46)
Tripartite efflux pumps in Gram-negative bacteria span the inner membrane, periplasm, and outer membrane, consisting of an inner-membrane transporter, a periplasmic adaptor protein, and an outer-membrane channel. In P. putida KT2440, the ABC-type tripartite pump PvdRT–OpmQ is described as a transporter responsible for secretion of newly synthesized and recycled pyoverdine. (stein2023therndefflux pages 1-2)
Within this system, PvdT is identified as the inner-membrane ABC ATPase component (MacB-like architecture) that energizes export by ATP hydrolysis and forms a functional complex with the periplasmic adaptor PvdR (and the outer-membrane channel OpmQ for full tripartite transport). (stein2023navigatingpyoverdineand pages 29-31, stein2023navigatingpyoverdineand pages 43-46)
Multiple sources in the retrieved corpus explicitly frame PvdRT–OpmQ as mediating pyoverdine secretion, including both “newly synthesized” and “recycled” pyoverdine in P. putida KT2440. (stein2023therndefflux pages 1-2)
Biochemical experiments described in a 2023 dissertation provide direct interaction/ligand evidence consistent with pyoverdine as the relevant substrate/ligand for the PvdT-containing complex. Specifically, pyoverdine affected ATPase kinetics and strengthened interaction parameters between the inner-membrane component (PvdT) and adaptor protein (PvdR), consistent with substrate-stabilized assembly and/or coupling. (stein2023navigatingpyoverdineand pages 46-49)
PvdT is an inner-membrane component of the PvdRT–OpmQ exporter; together with PvdR (periplasmic adaptor) and OpmQ (outer-membrane channel), the complex supports export to the extracellular milieu. This is visually summarized in schematic models of efflux-pump organization and pyoverdine secretion networks in KT2440. (stein2023navigatingpyoverdineand pages 29-31, stein2023navigatingpyoverdineand media 41401d62, stein2023navigatingpyoverdineand media 1c3e68be)
A key recent biochemical result is quantitative ATPase characterization showing that complex formation and pyoverdine presence measurably alter catalytic parameters:
Interpreting these results at the functional-annotation level: (i) PvdT is an ATP-hydrolyzing component consistent with an ABC exporter; (ii) adaptor complexation changes ATPase behavior; and (iii) pyoverdine can modulate these parameters, consistent with it being a cognate ligand/substrate that couples to complex assembly and/or transport activity. (stein2023navigatingpyoverdineand pages 46-49)
Deletion/inactivation evidence indicates PvdRT–OpmQ is important but not unique for pyoverdine export:
A 2023 KT2440-focused body of work reports biochemical interaction evidence between the PvdRT–OpmQ system and pyoverdine and provides quantitative ATPase kinetics (above), supporting a substrate-coupled transporter model for PvdT within this exporter. (stein2023navigatingpyoverdineand pages 46-49, stein2023navigatingpyoverdineand pages 43-46)
A 2023 peer-reviewed study (Microbiology Spectrum) frames pyoverdine export as a property of overlapping efflux systems, and emphasizes that phenotypes can be masked unless multiple exporters are perturbed—important context for annotation and for experimental design (e.g., interpreting partial secretion phenotypes). (stein2023therndefflux pages 1-2)
A 2024 review highlights that secretion mechanisms remain incompletely understood across organisms and argues for deeper genetic and mechanistic study of siderophore synthesis/secretion genes as a route to applications across agriculture, medicine, and environmental contexts. (xie2024exploringthebiological pages 13-15)
Direct “productized” deployments specifically requiring P. putida PvdT are not established in the retrieved corpus; however, pyoverdine/siderophore production and (by implication) effective export are repeatedly positioned as enabling technologies in multiple domains:
Because export is required to place siderophores in the extracellular environment, PvdT-mediated function is best understood as an upstream enabler of these siderophore-dependent phenomena (iron capture, competition, and siderophore-based technologies), even when PvdT is not named in application papers. (stein2023therndefflux pages 1-2, stein2023navigatingpyoverdineand pages 22-25)
Gene: pvdT (PP_4210; UniProt Q88F88)
Recommended functional name: Pyoverdine export ATP-binding/permease protein PvdT (inner-membrane ABC/MacB-like subunit of PvdRT–OpmQ)
Primary function: ATP-dependent component of a tripartite exporter required for efficient secretion/export and recycling of pyoverdine in P. putida KT2440. (stein2023therndefflux pages 1-2, stein2023navigatingpyoverdineand pages 29-31)
Substrate (best supported): Pyoverdine (siderophore), supported by biochemical modulation of ATPase kinetics by pyoverdine and complex stabilization effects. (stein2023navigatingpyoverdineand pages 46-49)
Cellular localization: Inner membrane (as the ABC ATPase/TMD component of the tripartite system spanning inner membrane → periplasm (PvdR) → outer membrane (OpmQ)). (stein2023navigatingpyoverdineand pages 29-31, stein2023navigatingpyoverdineand media 41401d62)
Pathway role: Siderophore secretion/export and recycling within pyoverdine-mediated iron acquisition; contributes substantially but redundantly (overlapping with other efflux systems). (stein2023therndefflux pages 1-2, stein2023navigatingpyoverdineand pages 29-31)
| Source (first author, year) | Publication type | Organism/strain | What it says about PvdT/PvdRT-OpmQ (function/substrate/localization) | Key quantitative data | URL/DOI |
|---|---|---|---|---|---|
| Stein, 2023 | Dissertation | Pseudomonas putida KT2440 | Identifies PvdT as the inner-membrane ABC ATPase component of the tripartite exporter PvdRT-OpmQ. The system is described as a MacB-like/ABC tripartite exporter involved in export and recycling of the siderophore pyoverdine; PvdT works with periplasmic adapter PvdR and outer-membrane channel OpmQ to move substrate to the exterior. Biochemical interaction data support pyoverdine as a ligand/substrate and support PvdT-PvdR complex formation. Deletion phenotypes are consistent with a major but non-exclusive role in pyoverdine secretion. (stein2023navigatingpyoverdineand pages 46-49, stein2023navigatingpyoverdineand pages 29-31, stein2023navigatingpyoverdineand pages 43-46, stein2023navigatingpyoverdineand pages 49-52) | Deletion of PvdRT-OpmQ reduces pyoverdine secretion by ~50–60%; purification yielded 0.2–0.4 mg PvdR/PvdT from 45 mg total membrane protein. ATPase kinetics reported for PvdT and PvdRT with/without pyoverdine: PvdT Vmax 9.91, KM 0.16 mM, kcat 0.08 s-1, kcat/KM 583.6 M-1 s-1; PvdRT Vmax 69.97, KM 2.58 mM, kcat 0.58 s-1, kcat/KM 214.2 M-1 s-1; PvdT+pyoverdine Vmax 6.43, KM 0.06 mM, kcat 0.05 s-1, kcat/KM 955.9 M-1 s-1; PvdRT+pyoverdine Vmax 40.41, KM 1.30 mM, kcat 0.34 s-1, kcat/KM 241.7 M-1 s-1. (stein2023navigatingpyoverdineand pages 46-49, stein2023navigatingpyoverdineand pages 29-31, stein2023navigatingpyoverdineand pages 43-46) | https://doi.org/10.5282/edoc.32605 |
| Stein, 2023 | Peer-reviewed research article (Microbiology Spectrum) | Pseudomonas putida KT2440 | States that the ABC-type tripartite efflux system PvdRT-OpmQ mediates secretion of newly synthesized and recycled pyoverdine. Loss of these systems impairs pyoverdine secretion and growth under iron limitation, but effects are partial because of redundancy with other tripartite exporters such as MdtABC-OpmB and ParXY. The excerpt does not resolve subunit-level localization beyond the general tripartite architecture spanning inner membrane, periplasm, and outer membrane. (stein2023therndefflux pages 15-16, stein2023therndefflux pages 1-2) | No PvdT-specific kinetic or binding values in the available snippet; qualitative evidence indicates impaired secretion and iron-limited growth upon inactivation of relevant systems, with partial redundancy. (stein2023therndefflux pages 15-16, stein2023therndefflux pages 1-2) | https://doi.org/10.1128/spectrum.02300-23 |
Table: This table summarizes the source-backed evidence available in context for PvdT/PvdRT-OpmQ in Pseudomonas putida KT2440. It highlights what each source supports about transporter function, substrate, localization, and any quantitative data useful for functional annotation.
A 2023 FEBS Letters primary article on purification/initial characterization of PvdRT–OpmQ in KT2440 is referenced within the retrieved corpus but was not directly obtainable in this run; thus, the report relies on the 2023 dissertation’s quantitative biochemical data and a 2023 peer-reviewed study’s contextual and genetic claims for KT2440, plus recent high-authority reviews for broader pathway synthesis. (stein2023therndefflux pages 15-16, stein2023navigatingpyoverdineand pages 46-49, schalk2025bacterialsiderophoresdiversity pages 46-46)
References
(stein2023navigatingpyoverdineand pages 29-31): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(stein2023therndefflux pages 1-2): Nicola Victoria Stein, Michelle Eder, Fabienne Burr, Sarah Stoss, Lorenz Holzner, Hans-Henning Kunz, and Heinrich Jung. The rnd efflux system parxy affects siderophore secretion in pseudomonas putida kt2440. Dec 2023. URL: https://doi.org/10.1128/spectrum.02300-23, doi:10.1128/spectrum.02300-23. This article has 8 citations and is from a domain leading peer-reviewed journal.
(schalk2025bacterialsiderophoresdiversity pages 46-46): Isabelle J. Schalk. Bacterial siderophores: diversity, uptake pathways and applications. Nature reviews. Microbiology, 23:24-40, Sep 2025. URL: https://doi.org/10.1038/s41579-024-01090-6, doi:10.1038/s41579-024-01090-6. This article has 211 citations.
(stein2023navigatingpyoverdineand pages 43-46): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(stein2023navigatingpyoverdineand pages 46-49): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(stein2023navigatingpyoverdineand media 41401d62): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(stein2023navigatingpyoverdineand media 1c3e68be): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(xie2024exploringthebiological pages 13-15): Benkang Xie, Xinpei Wei, Chu Wan, Wei Zhao, Renfeng Song, Shuquan Xin, and Kai Song. Exploring the biological pathways of siderophores and their multidisciplinary applications: a comprehensive review. Molecules, 29:2318, May 2024. URL: https://doi.org/10.3390/molecules29102318, doi:10.3390/molecules29102318. This article has 75 citations.
(stein2023navigatingpyoverdineand pages 22-25): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(schalk2025bacterialsiderophoresdiversity pages 12-14): Isabelle J. Schalk. Bacterial siderophores: diversity, uptake pathways and applications. Nature reviews. Microbiology, 23:24-40, Sep 2025. URL: https://doi.org/10.1038/s41579-024-01090-6, doi:10.1038/s41579-024-01090-6. This article has 211 citations.
(schalk2025bacterialsiderophoresdiversity pages 38-42): Isabelle J. Schalk. Bacterial siderophores: diversity, uptake pathways and applications. Nature reviews. Microbiology, 23:24-40, Sep 2025. URL: https://doi.org/10.1038/s41579-024-01090-6, doi:10.1038/s41579-024-01090-6. This article has 211 citations.
(xie2024exploringthebiological pages 15-17): Benkang Xie, Xinpei Wei, Chu Wan, Wei Zhao, Renfeng Song, Shuquan Xin, and Kai Song. Exploring the biological pathways of siderophores and their multidisciplinary applications: a comprehensive review. Molecules, 29:2318, May 2024. URL: https://doi.org/10.3390/molecules29102318, doi:10.3390/molecules29102318. This article has 75 citations.
(stein2023navigatingpyoverdineand pages 49-52): Nicola Victoria Maria Stein. Navigating pyoverdine and beyond: the role of tripartite efflux pumps in pseudomonas putida kt2440. Dissertation, Jan 2023. URL: https://doi.org/10.5282/edoc.32605, doi:10.5282/edoc.32605. This article has 1 citations.
(stein2023therndefflux pages 15-16): Nicola Victoria Stein, Michelle Eder, Fabienne Burr, Sarah Stoss, Lorenz Holzner, Hans-Henning Kunz, and Heinrich Jung. The rnd efflux system parxy affects siderophore secretion in pseudomonas putida kt2440. Dec 2023. URL: https://doi.org/10.1128/spectrum.02300-23, doi:10.1128/spectrum.02300-23. This article has 8 citations and is from a domain leading peer-reviewed journal.