Autotransporter secretion: varying on a theme

• Published in: Research in microbiology Vol. 164; no. 6; pp. 562 - 582
• Main Authors: Grijpstra, Jan, Arenas, Jesús, Rutten, Lucy, Tommassen, Jan
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.07.2013
• Subjects: Autotransporter; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacterial Secretion Systems; Bam complex; Cell Membrane - chemistry; Cell Membrane - genetics; Cell Membrane - metabolism; Chaperone; Gram-Negative Bacteria - chemistry; Gram-Negative Bacteria - genetics; Gram-Negative Bacteria - metabolism; Membrane Transport Proteins - chemistry; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Outer membrane; Protein secretion; Protein Structure, Tertiary; Protein Transport; Protein secretion; Bam complex; Autotransporter; Chaperone; Outer membrane
• ISSN: 0923-2508; 1769-7123
• DOI: 10.1016/j.resmic.2013.03.010

Autotransporters are widely distributed among Gram-negative bacteria. They can have a large variety of functions and many of them have a role in virulence. They are synthesized as large precursors with an N-terminal signal sequence that mediates transport across the inner membrane via the Sec machinery and a translocator domain that mediates the transport of the connected passenger domain across the outer membrane to the bacterial cell surface. Like integral outer membrane proteins, the translocator domain folds in a β-barrel structure and requires the Bam machinery for its insertion into the outer membrane. After transport across the outer membrane, the passenger may stay connected via the translocator domain to the bacterial cell surface or it is proteolytically released into the extracellular milieu. Based on the size of the translocator domain and its position relative to the passenger in the precursor, autotransporters are divided into four sub-categories. We review here the current knowledge of the biogenesis, structure and function of various autotransporters.