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Branched Chain Amino Acid Exporter (LIV-E) Family

bacterial protein family

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General referenceInterpretive dossier study · Crown Archives visual atlas
Record originEnglish Wikipedia
Text licenseCC BY-SA 4.0
Source revisionMar 6, 2026
Entity authorityQ126453992 ↗
Source-derived summary

Specific transmembrane protein complexes called Branched Chain Amino Acid Exporters (LIV-E) mediate the export of branched chain amino acids out of prokaryotic cells.

Branched chain amino acids (BCAAs) — isoleucine, leucine, and valine — are critical nutrients in bacterial physiology with roles in protein synthesis and signalling. Regulating the cytosolic level of BCAAs is necessary for cell growth and adaptation. LIV-E transporters are categorized as electrochemical potential-driven transporters, subcategory porters (2.A.78) in the Transporter Classification Database. LIV-E transporters are antiporters that use the proton motive force, catalyzing the import of two hydrogen ions into the cell, to obtain the energy to export one amino acid out of the cell.

All LIV-E complexes are formed from two separate transmembrane proteins. Though no structure of a LIV-E transporter exists, both proteins are necessary for function, and it is assumed they form a heterodimeric complex within the membrane.

Phylogeny

One study in the early 2000s investigated the phylogeny of the LIV-E family. It found that LIV-E transporters are prevalent across many prokaryotic organisms, including archaea and both Gram-positive and Gram-negative bacteria. While many species only encode one LIV-E transporter, other species encode multiple paralogs.

Editorial summary

The public source identifies “Branched Chain Amino Acid Exporter (LIV-E) Family” as bacterial protein family. This brief keeps that definition visible, then builds a research path around Branched, Chain and Amino.

Editorial reviewA concise reference frame for defining the subject, testing terminology and identifying the institution closest to the evidence. The current 191-word lead offers orientation but no explicit four-digit date, so chronology should not be assumed. The selected authority fields contribute no independent date. Its value is orientation rather than verdict, with Branched, Chain and Amino providing the first useful test.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Mar 6, 2026. The linked authority identifier is Q126453992. None of the 0 selected statements returned an explicit reference.

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Source & attribution

This entry incorporates text from “Branched Chain Amino Acid Exporter (LIV-E) Family” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.