A recent article by the CAZy team defines subfamilies within the large GH43 family.
Details appear in Mewis K, Lenfant N, Lombard V, Henrissat B. (2016) Dividing the large glycoside hydrolase family 43 into subfamilies: a motivation for detailed enzyme characterization. Appl Environ Microbiol. 2016 Jan 4. [PMID: 26729713 ]. The GH43 subfamilies now appear online at URL http://www.cazy.org/GH43_subfamilies.html