Bacterial lipoproteins are characterized by the presence of a conserved N-terminal lipid-modified cysteine residue that allows the hydrophilic protein to anchor into bacterial cell membranes. These lipoproteins play essential roles in a wide variety of physiological processes. Based on transcriptome analysis of the verrucomicrobial methanotrophMethylacidiphilum fumariolicumSolV, we identified a highly expressed lipoprotein, WP_009060351 (139 amino acids), in its genome. The first 86 amino acids are specific for the methanotrophic generaMethylacidiphilumandMethylacidmicrobium, while the last 53 amino acids are present only in lipoproteins of members from the phylum Verrucomicrobiota (Hedlund). Heterologous expression of WP_009060351 inEscherichia colirevealed a 25-kDa dimeric protein and a 60-kDa tetrameric protein. Immunoblotting showed that WP_009060351 was present in the total membrane protein and peptidoglycan fractions ofM. fumariolicumSolV. The results suggest an involvement of lipoprotein WP_009060351 in the linkage between the outer membrane and the peptidoglycan.