Pattern recognition receptor (PRR) located on the cell surface that participates in the activation of innate immunity and inflammatory response. Recognizes small molecular motifs named pathogen-associated molecular pattern (PAMPs) expressed by pathogens and microbe-associated molecular patterns (MAMPs) usually expressed by resident microbiota. Upon ligand binding such as bacterial flagellins, recruits intracellular adapter proteins MYD88 and TRIF leading to NF-kappa-B activation, cytokine secretion and induction of the inflammatory response. Plays thereby an important role in the relationship between the intestinal epithelium and enteric microbes and contributes to the gut microbiota composition throughout life. Homodimer. Interacts with MYD88 (via TIR domain). Interacts with TICAM1 (via TIR domain). Interacts with UNC93B1; this interaction is essential for proper TLR5 localization to the plasma membrane. Highly expressed in liver (PubMed:30089902). Detected in lung and at very low levels in most other tissues. Phosphorylated at Tyr-799 upon flagellin binding; required for signaling. The TLR5 gene lies in a locus that is associated with susceptibility to Salmonella. Inbred strains of mice can be classified into 3 categories according to their resistance to infection with S.typhimurium: susceptible (BALB/c, C57BL/6, C3H/He), intermediate (DBA/2, C75L) and resistant (A, CBA). The strain MOLF/Ei is highly susceptible to the infection, has an unique TLR5 haplotype and a lower expression of TRL5. Deficient mice exhibit a markedly altered enteric microbiota composition, with increased levels of fecal flagellin. Belongs to the Toll-like receptor family.