Bacterial long-chain fatty acid transport. Identification of amino acid residues within the outer membrane protein FadL required for activity

G. B. Kumar, P. N. Black

Research output: Contribution to journalArticle

45 Scopus citations


The outer membrane protein FadL (product of the fadL gene) of Escherichia coli is required for the specific binding and transport of exogenous long- chain fatty acids prior to metabolic utilization. The carboxyl end of FadL has been proposed to play a crucial role by facilitating the transport of long-chain fatty acids. In an attempt to define specific amino acid residues within carboxyl region of FadL essential for activity, a series of deletion and point mutations within the 3' end of the fadL+ gene have been constructed and characterized. These fadL mutants were classified into three categories based on functional properties attributable to the altered FadL proteins: (i) those that had essentially wild-type levels of long-chain fatty acid binding and transport, (ii) those that had wild-type levels of long-chain fatty acid binding but were defective in transport, and (iii) those that were defective for both long-chain fatty acid binding and transport. These findings demonstrate that amino acid residues Phe448, Pro428, Val410, and Ser397 are required for optimal levels of long- chain fatty acid transport and that amino acid residues Pro428 and Val410 are essential for long-chain fatty acid binding.

Original languageEnglish (US)
Pages (from-to)15469-15476
Number of pages8
JournalJournal of Biological Chemistry
Issue number21
Publication statusPublished - Jan 1 1993


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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