This entry represents bacterial lipoproteins that belong to the NlpA family [1,2]. It contains several antigenic members, that may be involved in bacterial virulence. This entry includes the D-methionine binding lipoprotein MetQ, which is the substrate-binding component of a D-methionine permease, a binding protein-dependent, ATP-driven transport system [2,3]. Other members of this family, such as NlpA, have been identified as putative substrate-binding components of ABC transporters. NlpA, is an inner-membrane-anchored lipoprotein that has been shown to have a minor role in methionine import [4,5].

1: Lipoprotein-28, a cytoplasmic membrane lipoprotein from Escherichia coli. Cloning, DNA sequence, and expression of its gene. Yu F, Inouye S, Inouye M; J Biol Chem 1986;261:2284-2288. PMID:3003106

2: The metD D-methionine transporter locus of Escherichia coli is an ABC transporter gene cluster. Gal J, Szvetnik A, Schnell R, Kalman M; J Bacteriol. 2002;184:4930-4932. PMID:12169620

3: Noncanonical role for the binding protein in substrate uptake by the MetNI methionine ATP Binding Cassette (ABC) transporter. Nguyen PT, Lai JY, Lee AT, Kaiser JT, Rees DC; Proc Natl Acad Sci U S A. 2018;115:E10596. PMID:30352853

4: Synthetic effect between envelope stress and lack of outer membrane vesicle production in Escherichia coli. Schwechheimer C, Kuehn MJ; J Bacteriol. 2013;195:4161-4173. PMID:23852867

5: A transporter of Escherichia coli specific for L- and D-methionine is the prototype for a new family within the ABC superfamily. Zhang Z, Feige JN, Chang AB, Anderson IJ, Brodianski VM, Vitreschak AG, Gelfand MS, Saier MH Jr; Arch Microbiol. 2003;180:88-100. PMID:12819857