GO:0015594 ABC-type putrescine transporter activity

ABC-type putrescine transporter activity (GO:0015594) is a molecular function in which an ATP-binding cassette transporter uses the energy of ATP hydrolysis to move putrescine from the outside of a membrane to the inside. Putrescine is a polyamine, and its uptake is part of the broader polyamine transport and utilization machinery that bacteria use to scavenge and balance intracellular polyamine pools. The QuickGO definition specifies the exact reaction: putrescine(out) + ATP + H2O = putrescine(in) + ADP + phosphate + H+. This makes GO:0015594 a primary active transport activity rather than a passive diffusion or secondary carrier function. Researchers study GO:0015594 because polyamine uptake systems influence bacterial growth, stress responses, and host interaction. In Pseudomonas aeruginosa PAO1, the divergent spuABCDEFGH-spuI operons were functionally analyzed and shown to support polyamine uptake and utilization, providing direct genetic evidence for an ABC-type putrescine transport system. In Clostridioides difficile, the response regulator RR_1586 was found to regulate target genes that include transport functions, indicating that ABC-type transporter expression can be wired into two-component regulatory circuits. More broadly, functional characterization of ABC transporter operons such as oppABCDF-1 in Escherichia coli Nissle 1917 demonstrates how solute uptake systems are dissected genetically and biochemically. For biomedical researchers, GO:0015594 is a precise annotation that can be used to interpret transcriptomic, proteomic, and genetic screens. When a gene is annotated with GO:0015594, it predicts a specific biochemical activity: ATP-dependent putrescine import. This matters for studies of polyamine metabolism, antimicrobial target discovery, and microbial adaptation, because disrupting putrescine uptake can alter polyamine homeostasis and downstream phenotypes. The term also provides a controlled vocabulary for comparing transport systems across species, as illustrated by functional work on ABC-type transporters in E. coli Nissle 1917 and regulatory studies in C. difficile.

GO:0015594, ABC-type putrescine transporter activity, is defined as the catalysis of the reaction putrescine(out) + ATP + H2O = putrescine(in) + ADP + phosphate + H+. In plain terms, it is an ATP-powered pump that imports putrescine into a cell or compartment while hydrolyzing ATP. The activity is classified as a molecular_function in the Gene Ontology and is synonymous with ATPase-coupled putrescine transmembrane transporter activity, putrescine-importing ATPase activity, and putrescine porter activity. It belongs to the broader class of ABC-type transporters, which use ATP binding and hydrolysis to drive substrate translocation.

GO:0015594 is important because putrescine uptake directly affects polyamine homeostasis, which in turn influences bacterial growth, stress resistance, and interactions with host cells. The spuABCDEFGH-spuI operons in Pseudomonas aeruginosa PAO1 provide a genetically defined example of a polyamine uptake and utilization system that includes ABC-type putrescine transport components. Because ABC transporters are often regulated by dedicated response regulators, as shown for RR_1586 in Clostridioides difficile, the activity is also a node where environmental signals are converted into transport capacity. Understanding this activity can inform studies of microbial physiology, antibiotic target discovery, and the functional annotation of transporter operons such as oppABCDF-1 in Escherichia coli Nissle 1917.

The following genes and proteins are associated with ABC-type putrescine transporter activity or with the polyamine uptake and regulatory systems that support it, based on the verified literature.

The expression and activity of ABC-type putrescine transporter systems are subject to regulation. In Pseudomonas aeruginosa PAO1, the divergent spuABCDEFGH-spuI operons for polyamine uptake and utilization are regulated, linking transporter production to polyamine availability. In Clostridioides difficile, the response regulator RR_1586 regulates target genes that include transport-related functions, demonstrating that two-component signaling can control ABC-type transporter expression. These examples show that GO:0015594 activity is not constitutive but is tuned by regulatory networks that sense environmental and metabolic cues.

Polyamine uptake systems can influence bacterial physiology and host interaction. In Pseudomonas aeruginosa PAO1, the spuABCDEFGH-spuI operons support polyamine uptake and utilization, processes that contribute to bacterial fitness. Because ABC-type putrescine transporter activity supplies putrescine, it may affect phenotypes relevant to infection, although direct disease causation for GO:0015594 itself is not established in the verified literature.

Clostridioides difficile is a clinically important pathogen, and its response regulator RR_1586 regulates target genes including transport functions. This suggests that ABC-type transporter expression is integrated into regulatory networks that could influence C. difficile biology. However, the verified literature does not directly link GO:0015594 to a specific human disease outcome.

ABC transporters are attractive targets because they consume ATP and perform essential uptake functions. Functional characterization of oppABCDF-1 in Escherichia coli Nissle 1917 shows how ABC transporter operons can be studied in probiotic and pathogenic contexts. Such work provides a framework for evaluating whether putrescine transporters could be targeted, but clinical relevance remains to be established.

Knockout of candidate genes followed by complementation is a standard approach to test whether a gene is required for ABC-type putrescine transporter activity. In Pseudomonas aeruginosa PAO1, functional analysis of the spuABCDEFGH-spuI operons used genetic approaches to link these genes to polyamine uptake and utilization. Similar strategies can be applied to any gene annotated with GO:0015594.

Direct transport assays measure putrescine import and can distinguish ATP-dependent uptake from passive diffusion. The QuickGO reaction for GO:0015594 specifies putrescine(out) to putrescine(in) movement, providing a biochemical readout. Such assays are essential to confirm that a candidate transporter has the annotated activity.

Bacterial one-hybrid screens and related methods can identify regulators that control transporter expression. In Clostridioides difficile, a bacterial one-hybrid screen identified regulatory targets of RR_1586, including transport-related functions. This approach helps place GO:0015594 within a regulatory network.

Operon-level characterization, as performed for oppABCDF-1 in Escherichia coli Nissle 1917, provides a template for studying ABC transporter systems. Combining deletion analysis, expression studies, and biochemical assays can define the roles of individual components. These methods are directly transferable to putrescine transporter research.

Researchers studying ABC-type putrescine transporter activity-related genes often need to determine whether a candidate gene is causally involved in putrescine import, how its domains contribute to ATP-coupled transport, and how its expression is regulated. EDITGENE provides CRISPR-based cell models and screening services that allow these questions to be addressed with reproducible, publication-ready experimental systems.

GO:0015594, ABC-type putrescine transporter activity, defines a specific ATP-dependent transport function that imports putrescine across a membrane. Its mechanism is rooted in ABC transporter biochemistry, with ATP hydrolysis coupled to substrate translocation. Genetic studies of the spuABCDEFGH-spuI operons in Pseudomonas aeruginosa PAO1 and regulatory analysis of RR_1586 in Clostridioides difficile provide experimental frameworks for understanding how this activity is encoded and controlled. Functional characterization of ABC transporter operons such as oppABCDF-1 in Escherichia coli Nissle 1917 further illustrates how these systems can be dissected. Together, these studies support precise annotation and hypothesis-driven research on putrescine transport.