Functional analysis of the N‐terminal region of acetylxylan esterase from Caldanaerobacter subterraneus subsp. tengcongensis. Issue 10 (20th September 2022)

• Record Type: Journal Article
• Authors: Sasamoto, Kohei; Himiyama, Tomoki; Moriyoshi, Kunihiko; Ohmoto, Takashi; Uegaki, Koichi; Nakamura, Tsutomu; Nishiya, Yoshiaki
• Is Part Of: FEBS open bio. Volume 12:Issue 10(2022)
• Page Start: 1875
• Page End: 1885
• Publication Date: 2022-09-20
• Subjects: acetylxylan esterase -- Caldanaerobacter -- crystallization -- intrinsically disordered region -- protein solubility; Molecular biology -- Periodicals; Cytology -- Periodicals; Life sciences -- Periodicals; Biological Science Disciplines -- Periodicals; Molecular Biology -- Periodicals; Cell Biology -- Periodicals; Cytology; Life sciences; Molecular biology; Periodicals; 572.805
• DOI: 10.1002/2211-5463.13476
• Languages: English
• ISSNs: 2211-5463

Abstract

Abstract : Acetylxylan esterase from Caldanaerobacter subterraneus subsp. tengcongensis (TTE0866) has an N‐terminal region (NTR; residues 23–135) between the signal sequence (residues 1–22) and the catalytic domain (residues 136–324), which is of unknown function. Our previous study revealed the crystal structure of the wild‐type (WT) enzyme containing the NTR and the catalytic domain. Although the structure of the catalytic domain was successfully determined, that of the NTR was undetermined, as its electron density was unclear. In this study, we investigated the role of the NTR through functional and structural analyses of NTR truncation mutants. Based on sequence and secondary structure analyses, NTR was confirmed to be an intrinsically disordered region. The truncation of NTR significantly decreased the solubility of the proteins at low salt concentrations compared with that of the WT. The NTR‐truncated mutant easily crystallized in a conventional buffer solution. The crystal exhibited crystallographic properties comparable with those of the WT crystals suitable for structural determination. These results suggest that NTR plays a role in maintaining the solubility and inhibiting the crystallization of the catalytic domain. Abstract : Acetylxylan esterase from Caldanaerobacter subterraneus subsp. tengcongensis (TTE0866) has a functionally unknown, intrinsically disordered N‐terminal region (NTR). In this article, we report that NTR plays a role in maintaining the solubility and inhibiting the crystallization of the catalytic domain. These findings provide new insights into the role of the NTR region in carbohydrate‐active enzymes.