This family consists of bacterial cutinases (EC:3.1.1.74), which catalyse the hydrolysis of cutin, a polyester that forms the structure of plant cuticle [1,2]. These enzymes also show esterase activity towards p-nitrophenol-linked aliphatic esters [3,4]. Cutinase est2 can also depolymerize the synthetic polyesters poly(epsilon-caprolactone) (PCL), poly(butylene succinate-co-adipate) (PBSA), poly(butylene succinate) (PBS), and poly(lactic acid) (PLA) [5,6,7]. Members of this family are able to degrade the plastic poly(ethylene terephthalate) (PET).

1: Structural and functional studies on a thermostable polyethylene terephthalate degrading hydrolase from Thermobifida fusca. Roth C, Wei R, Oeser T, Then J, Follner C, Zimmermann W, Strater N; Appl Microbiol Biotechnol. 2014;98:7815-7823. PMID:24728714

2: Small cause, large effect: Structural characterization of cutinases from Thermobifida cellulosilytica. Ribitsch D, Hromic A, Zitzenbacher S, Zartl B, Gamerith C, Pellis A, Jungbauer A, Lyskowski A, Steinkellner G, Gruber K, Tscheliessnig R, Herrero Acero E, Guebitz GM; Biotechnol Bioeng. 2017;114:2481-2488. PMID:28671263

3: Comparison of genetic structures and biochemical properties of tandem cutinase-type polyesterases from Thermobifida alba AHK119. Thumarat U, Kawabata T, Nakajima M, Nakajima H, Sugiyama A, Yazaki K, Tada T, Waku T, Tanaka N, Kawai F; J Biosci Bioeng. 2015;120:491-497. PMID:25910960

4: Decolorization of molasses alcohol wastewater by thermophilic hydrolase with practical application value. Zhang Z, Wang W, Li D, Xiao J, Wu L, Geng X, Wu G, Zeng Z, Hu J; Bioresour Technol. 2021;323:124609. PMID:33387709

5: Diversity of polyester-degrading bacteria in compost and molecular analysis of a thermoactive esterase from Thermobifida alba AHK119. Hu X, Thumarat U, Zhang X, Tang M, Kawai F; Appl Microbiol Biotechnol. 2010;87:771-779. PMID:20393707

6: Biochemical and genetic analysis of a cutinase-type polyesterase from a thermophilic Thermobifida alba AHK119. Thumarat U, Nakamura R, Kawabata T, Suzuki H, Kawai F; Appl Microbiol Biotechnol. 2012;95:419-430. PMID:22183084

7: Structural insights into the unique polylactate-degrading mechanism of Thermobifida alba cutinase. Kitadokoro K, Kakara M, Matsui S, Osokoshi R, Thumarat U, Kawai F, Kamitani S; FEBS J. 2019;286:2087-2098. PMID:30761732