Sandbox Reserved 655: Difference between revisions

In the past 20 years, researchers have found that endoglucanases cannot break down polysaccharides efficiently without the help of non-catalytic carbohydrate-binding modules. Thus, the 59kDa endoglucanase is mostly found in the form of a complex that is made up of two to three separate domains. The main domain contains the large, globular catalytic domain which expresses the active site. The catalytic module of members of GH family 9 shows an (alpha/alpha)6-barrel structure. The 12 alpha-helices display an alternating connection pattern between outer and inner helices, as is common in (alpha/alpha)6-barrel structures (Parsiegla et al., 1998). The barrel is formed by the parallel inner helices 2, 4, 6, 8, 10 and 12. Besides the 12 alpha-helices, the catalytic module of Aa_Cel9A shows two antiparallel beta-strands and three short alpha-helices which are structurally conserved throughout the family 9 cellulases.A loop of the protein chain forms a tunnel that encloses the <scene name='Sandbox_Reserved_655/Active_site/1'>active site</scene>.  

This is attached at the O-glycosylated B block hinge region of the catalytic domain to the smaller, globular CBM at its C-terminal A block by a linker peptide made up of proline, serine, and threonine (Nimlos, et al., 2007).[[Image:CBM.jpg]]