In other cases the comments may indicate, for example, that a particular enzyme is a flavoprotein or that it requires Zn+, or they may mention the variations in specificity found in different organisms. The list of other names of hexokinase hints (“type IV”) at the variety of isoenzymes known. However, it is hardly practical to deal with isoenzymes in any systematic way, not only because of the great increase in complexity of the list as a whole that it would entail, but also because nature itself is not systematic. Although all vertebrates contain hexokinase, and all known

vertebrates contain isoenzymes of hexokinase, there is great variation, even between similar species, in the particular isoenzymes present. This

type of complexity is best dealt with by supplying a suitable reference, in this case to Ref. 5 of the list. As already noted, PD0325901 datasheet classification and definitive naming of new enzyme activities is the task of the Nomenclature Committee of the IUBMB. A certain proportion of new entries result from searches of the literature by find more the members of the Committee or by people involved in compiling databases such as BRENDA (Scheer et al., 2011). However, it is obviously more efficient if new activities are directly reported by the researchers who discover and publish them, using the form at http://www.enzyme-database.org/newform.php. Likewise researchers who find errors or omissions in existing entries can report them on the form at http://www.enzyme-database.org/updateform.php.16 The information requested for a new enzyme activity is as follows: • Proposed sub-subclass (e.g. EC 1.2.3.–). Note that there is no field

for the fourth number, which should not be suggested. Although the reaction Resveratrol catalysed is the only required item, in practice at least one reference should be given, and suggested entries are only likely to be accepted if they are supported by at least one paper that is published or in press (“in preparation”, “submitted for publication”, “personal communication”, etc. are unlikely to be acceptable). Cofactor and specificity information should also be included if they are appropriate. In addition to information about the enzyme, contact details for the person suggesting the entry are also required: • Name (required) Published work cited should be submitted with the suggested entry. This can be done either by sending hard copies by post, or by attaching PDF files to e-mail messages. The addresses are given on the form, and at present are Andrew McDonald, Department of Biochemistry, Trinity College, Dublin 2, Ireland; fax: +353-1-6772400; e-mail: [email protected]. The form for reporting an error or suggesting a revision in an existing entry asks for the following information: (EC number, e.g. EC 1.2.3.4). In this case the complete four-part number is to be given as the change refers to an enzyme that has already been listed.