This is the beta-sheet domain found in rhamnogalacturonan (RG) lyases [1], which are responsible for an initial cleavage of the RG type I (RG-I) region of plant cell wall pectin. Polysaccharide lyase family 11 carrying this domain, such as YesW (EC:4.2.2.23) and YesX (EC:4.2.2.24), cleave glycoside bonds between rhamnose and galacturonic acid residues in RG-I through a beta-elimination reaction [2]. Other family members carrying this domain are hemagglutinin A, lysine gingipain (Kgp) [3] and Chitinase C (EC:3.2.1.14).

1: A novel structural fold in polysaccharide lyases: Bacillus subtilis family 11 rhamnogalacturonan lyase YesW with an eight-bladed beta-propeller. Ochiai A, Itoh T, Maruyama Y, Kawamata A, Mikami B, Hashimoto W, Murata K; J Biol Chem. 2007;282:37134-37145. PMID:17947240

2: Structural determinants responsible for substrate recognition and mode of action in family 11 polysaccharide lyases. Ochiai A, Itoh T, Mikami B, Hashimoto W, Murata K; J Biol Chem. 2009;284:10181-10189. PMID:19193638

3: STRUCTURE DETERMINATION AND ANALYSIS OF A HEMOLYTIC GINGIPAIN ADHESIN DOMAIN FROM PORPHYROMONAS GINGIVALIS. Li N, Yun P, Nadkarni MA, Ghadikolaee NB, Nguyen KA, Lee M, Hunter N, Collyer CA; Mol Microbiol. 2010; [Epub ahead of print] PMID:20233299

4: Design of thermostable rhamnogalacturonan lyase mutants from Bacillus licheniformis by combination of targeted single point mutations. Silva IR, Jers C, Otten H, Nyffenegger C, Larsen DM, Derkx PM, Meyer AS, Mikkelsen JD, Larsen S; Appl Microbiol Biotechnol. 2014;98:4521-4531. PMID:24419797