Table 2.

Sequence and structure comparison of the eight-residue loops of family 11 xylanases

Enzyme abbreviation	Source	PDB code	Eight-residue loop sequence	Salt-bridge in the eight-residue loop	Optimum pH
XynJ (∆XBD)	Bacillus sp. 41M-1	2DCK	QPSIKGTA	Lys135- Glu55	9 [17]
Xyl C	alkalophilic Bacillus (NCL 87-6-10)	2F6B	QPSIKGIA	Lys136-Glu56	8 [35]
BadX	Bacillus agaradhaerens AC13	1H4G	QPSIKGIA	Lys136- Glu56	8 [36]
Xyn11X	Bacillus subtilis B230	1IGO	QPSIIGIA	NA	8 [37]
Xyn11A-LC	Bacillus sp SN5	4IXL	QPSIEGTA	NA	7.5 [18]
XynA	Bacillus subtilis 168(1A1)	1XXN	APSIDGDR	NA	6–6.5 [38]
Xyl1	Streptomyces sp. S38	1HIX	APSVEGTK	NA	6 [39]
Bcx	Bacillus circulans	1XNB	APSIDGDR	NA	5.7 [40]
Xyn2	Hypocrea jecorina RUT-C30	1XYO	QPSIIGTA	NA	5.3 [21]
XYNI	Trichoderma reesei	1XYN	EPSIQGTA	NA	3.5 [41]
XYL1	Scytalidium acidophilum	3M4F	EPSITGTS	NA	3.2 [42]
XynA	Aspergillus niger CBS 513.88	1UKR	EPSITGTS	NA	3 [43]
XynC	Aspergillus kawachii	1BK1	EPSITGTS	NA	2 [44]

The key residues involved in the pH adaptation of enzymes are in bold and underlined