GO:0015411 ABC-type taurine transporter transporter activity

GO:0015411, ABC-type taurine transporter transporter activity, is a molecular_function term describing an ATP-driven transport activity that moves taurine from one side of a membrane to the other. The activity is defined by the coupled reaction ATP + H2O + taurine(out) = ADP + phosphate + taurine(in), meaning that taurine import is energetically linked to ATP hydrolysis. This places the term within the broader class of ATPase-coupled transporters, often called ABC transporters, which use nucleotide binding and hydrolysis to drive substrate translocation. Researchers encounter this term when annotating genes that mediate taurine uptake, particularly in bacteria that can use taurine as a sulfur source under sulfate limitation. In Escherichia coli, sulfate starvation-regulated genes include a gene cluster involved in the utilization of taurine as a sulfur source, providing direct experimental evidence that taurine transport and downstream sulfur mobilization are coordinated. Because taurine is a sulfonated amino acid, its uptake and subsequent desulfonation can supply sulfur when inorganic sulfate is scarce. The GO term therefore captures a specific membrane transport function that connects environmental sulfur availability to cellular metabolism. For genome biologists, correct annotation of GO:0015411 helps distinguish ATP-dependent taurine uptake from other taurine-related functions, such as taurine biosynthesis, taurine catabolism, or sodium-dependent taurine transport. This distinction matters when interpreting transcriptomic responses to sulfate starvation, when building metabolic models, and when designing genetic experiments to test whether a candidate gene is causally required for taurine-dependent growth. The term also provides a controlled vocabulary anchor for comparative genomics of sulfur acquisition across microbial taxa.

In plain terms, GO:0015411 means a membrane protein system that uses ATP to pull taurine into the cell. The official QuickGO definition states that this activity enables the transfer of taurine from one side of a membrane to the other according to the reaction ATP + H2O + taurine(out) = ADP + phosphate + taurine(in). It is an ATPase-coupled transporter activity, also known as ATP-dependent taurine transporter activity, taurine ABC transporter, or taurine-transporting ATPase activity. The term belongs to the molecular_function ontology and should not be confused with a biological process such as taurine metabolism or with a cellular component such as the plasma membrane. Functionally, the annotation implies three coupled features: taurine recognition, membrane translocation, and ATP hydrolysis. In Escherichia coli, genes in a sulfate starvation-regulated cluster are involved in taurine utilization as a sulfur source, which is consistent with an ATP-dependent taurine uptake step feeding sulfur metabolism.

GO:0015411 is important because it defines the molecular step by which cells can acquire taurine using ATP, linking membrane transport to sulfur metabolism and nutrient sensing. In bacteria such as Escherichia coli, the ability to use taurine as a sulfur source depends on sulfate starvation-regulated genes, and the taurine transporter activity is a key entry point for that pathway. Accurate annotation of this activity supports functional genomics, metabolic modeling, and experimental design aimed at understanding how cells respond to sulfur limitation. Because the term is a molecular_function annotation, it also helps researchers separate transport from downstream metabolic conversions when interpreting gene expression or mutant phenotypes.

The genes and proteins most directly associated with GO:0015411 are those in the sulfate starvation-regulated taurine utilization gene cluster of Escherichia coli, as identified in the verified literature.

The expression and activity of the taurine utilization system are regulated by sulfate starvation in Escherichia coli, as shown by the identification of sulfate starvation-regulated genes in a gene cluster involved in the utilization of taurine as a sulfur source. This means that when sulfate is scarce, the cell increases the capacity to acquire and use alternative sulfur sources such as taurine. The regulation is therefore tied to sulfur availability rather than to taurine alone. Researchers studying GO:0015411 should consider sulfur status as a key experimental variable when measuring transporter gene expression or activity.

GO:0015411 is directly linked to the ability of Escherichia coli to use taurine as a sulfur source under sulfate starvation. Disruption of this activity would be expected to impair growth when taurine is the main sulfur source, providing a model for studying nutrient-dependent growth. This has implications for understanding how bacteria adapt to sulfur-limited environments.

Taurine is abundant in some host environments, and the ability to transport and utilize it as a sulfur source may support microbial adaptation. The sulfate starvation-regulated gene cluster in Escherichia coli provides a genetic framework for testing whether taurine transport contributes to survival in sulfur-restricted niches. Such studies can inform research on microbial nutrient acquisition.

While the verified literature for GO:0015411 focuses on bacterial taurine utilization, the general principle of ATP-dependent taurine transport is relevant to understanding how cells regulate taurine levels. Researchers can use the bacterial system as a genetically tractable model to dissect the mechanism of ABC-type taurine transport. This mechanistic knowledge can guide hypothesis generation for other systems.

CRISPR knockout of genes in the Escherichia coli taurine utilization cluster can test whether the ABC-type taurine transporter activity is required for growth when taurine is the sole sulfur source. Growth assays under sulfate starvation conditions provide a direct phenotypic readout. Complementation with wild-type or mutant alleles can confirm specificity.

RNA-seq or transcriptional reporter fusions can measure how sulfate starvation regulates the taurine utilization gene cluster. The original identification of sulfate starvation-regulated genes in Escherichia coli used such approaches to define the gene cluster involved in taurine utilization. These methods help link transporter expression to environmental sulfur status.

Membrane vesicle or purified protein assays can measure ATP-dependent taurine transport and ATP hydrolysis. The GO:0015411 definition provides the expected reaction stoichiometry for such assays. These experiments directly test the molecular function.

Genome-wide annotation using GO:0015411 can identify taurine transporter candidates across microbial genomes. The Escherichia coli sulfate starvation-regulated cluster serves as a reference locus for comparative analysis. This supports functional prediction and experimental prioritization.

Researchers studying ABC-type taurine transporter transporter activity-related genes often need to determine whether a candidate gene is causally involved in taurine uptake, sulfur acquisition, or related phenotypes. EDITGENE provides CRISPR-based cell model services that enable knockout, point mutation, knock-in, overexpression, and library screening to test these hypotheses in a controlled genetic background.

GO:0015411, ABC-type taurine transporter transporter activity, defines an ATP-dependent membrane transport function that moves taurine into cells according to the reaction ATP + H2O + taurine(out) = ADP + phosphate + taurine(in). In Escherichia coli, this activity is part of a sulfate starvation-regulated gene cluster that enables taurine to be used as a sulfur source. Accurate annotation and experimental dissection of this term support studies of sulfur metabolism, nutrient acquisition, and ABC transporter mechanism. CRISPR-based knockout, point-mutation, knock-in, and overexpression models provide direct ways to test the causal role of candidate genes in this activity.