The role of Zn2+, dimerization and N-glycosylation in the interaction of Auxin-Binding Protein 1 (ABP1) with different auxins.

Publisher: IRL Press at Oxford University Press Country of Publication: England NLM ID: 9104124 Publication Model: Print Cited Medium: Internet ISSN: 1460-2423 (Electronic) Linking ISSN: 09596658 NLM ISO Abbreviation: Glycobiology Subsets: MEDLINE

Original Publication: Oxford ; New York : IRL Press at Oxford University Press, c1990-

Protein Multimerization*; Arabidopsis/*chemistry ; Arabidopsis Proteins/*chemistry ; Carrier Proteins/*chemistry ; Indoleacetic Acids/*chemistry ; Zea mays/*chemistry ; Zinc/*chemistry; Arabidopsis/genetics ; Arabidopsis/metabolism ; Arabidopsis Proteins/genetics ; Arabidopsis Proteins/metabolism ; Carrier Proteins/genetics ; Carrier Proteins/metabolism ; Glycosylation ; Indoleacetic Acids/metabolism ; Protein Domains ; Protein Structure, Secondary ; Zea mays/genetics ; Zea mays/metabolism ; Zinc/metabolism

Auxin is critical for plant growth and development. The main natural auxin is indole-3-acetic acid (IAA), whereas 1-naphthalene acetic acid (NAA) is a synthetic form. Auxin-Binding Protein 1 (ABP1) specifically binds auxins, presumably playing roles as receptor in nontranscriptional cell responses. ABP1 structure was previously established from maize at 1.9 Å resolution. To gain further insight on ABP1 structural biology, this study was carried out employing molecular dynamics simulations of the complete models of the oligomeric glycosylated proteins from maize and Arabidopsis thaliana with or without auxins. In maize, both Zn2+ coordination and glycosylation promoted conformational stability and most of such stabilization effect was located on the N-terminal region. The α-helix of C-terminal regions in ABP1 of both species unfolded during simulations, assuming a more extended structure in maize. In Arabidopsis, the helix appeared more stable, being preserved in most of the monomeric simulations and unfolding when the protein was in the dimeric form. In Arabidopsis ABP1 bound to IAA or NAA, glycosylation structures arranged around the protein, covering the putative site of entrance or egress of auxin. NAA bound protein folding was more similar to the crystal structure showing higher stability compared to that of IAA bound. The molecular structural differences of ABP1 found between the species and auxin types indicate that this auxin-binding protein shows functional specificities in dicots and monocots, as well as in auxin type binding.
(© The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Keywords: ABP1; Arabidopsis; Zea mays; auxin; glycan

0 (Arabidopsis Proteins)
0 (Carrier Proteins)
0 (Indoleacetic Acids)
J41CSQ7QDS (Zinc)

Date Created: 20171004 Date Completed: 20180709 Latest Revision: 20180730

20240829

10.1093/glycob/cwx080

28973586