10588
For wild type MutT and its E53D and E44D mutants , plots of log ( k ( cat ) ) versus pH exhibited a limiting slope of 1 on the ascending limb and then a hump , i . e . , a sharply defined maximum near pH 8 followed by a plateau , yielding apparent pK ( a ) values of 7 . 6 + / - 0 . 3 and 8 . 4 + / - 0 . 4 for an essential base and a nonessential acid catalyst , respectively , in the active quaternary MutT - Mg ( 2 + ) - dGTP - Mg ( 2 + ) complex .
 MutT, E53D, E44D mutants, MutT
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 MutT, E53D, E44D mutants, MutT