Small-angle X-ray scattering and structural modeling of full-length: cellobiohydrolase I from Trichoderma harzianum

Biophysical and biochemical studies of a major endoglucanase secreted by Xanthomonas campestris pv. campestris.

“…The size of the XccCel5A (D max = 115 Å) is almost the same as estimated from SAXS studies for T. harzianum Cel7A (D max = 110 Å) [46] and its molecular model is quite similar in its shape to the latter enzyme. Earlier reports described significantly larger molecular sizes for C. fimi endoglucanase (D max = 210 Å), T. reesei Cel7A (D max = 180 Å) and T. reesei Cel6A (D max = 215 Å) [43][44][45], although more recent electron microscopy studies defined T. reesei Cel7A and Cel6A D max as 151 ± 13 Å and 134 ± 26 Å, respectively [48].…”

“…6). Similar molecular shapes have already been reported for other cellulases [43][44][45][46][47][48][49]. Structural parameters for the XccCel5A obtained from SAXS analysis are summarized in Table 1.…”

Fungal Cellulases

“…Additional studies have been published that include SAXS analysis of intact cellulases with broadly similar conclusions. 414 Besides SAXS, NMR and MD simulation also been used to characterize linker behavior. Poon et al used NMR spectroscopy to examine the proline-threonine rich linker of a family 10 xylanase from C. f imi.…”

Estudos estruturais de hidrolases de glicosídeos em solução usando técnicas de espalhamento a baixo ângulo (SAS)

“…To this, the packages MASSHA (Konarev et al 2001), SASREF and BUNCH (Petoukhov and Svergun 2005) can be used. This approach has been successfully applied in our lab to several proteins before, leading in some cases to new and unexpected results (Rojas et al 2005;Grimm et al 2006;Santos et al 2012;Lima et al 2013).…”

“…It is known, for example, that cellulases have linkers of a different length, and that interaction with lignocellulose substrate and processivity of action are remarkably different for endoglucanases and exoglucanases, and even between two exoglucanases (CBH I and CBH II), but information on their molecular shape in full-length settings is not readily available for most of the enzymes and the influence of the linker flexibility and relative mobility of the correspondent CBMs on the interactions of the enzymes with their cognate substrates are not well understood as yet. In the recent publication (Lima et al 2013) showed, based on the small-angle X-ray scattering and molecular dynamics (MD) simulations that the optimum distance between CCD and CBM is determined by the minimum energy conformation of the linker which is influenced by its amino acid sequence and degree of glycosylation. The linker length and conformation influence relative mobility of CBM with respect to CCD and thus interaction of the cellulase with the solid polymeric substrate (cellulose).…”