Structural analysis and molecular model of a self-incompatibility RNase from wild tomato


Autoria(s): Parry, S; Newbigin, E; Craik, D; Nakamura, KT; Bacic, A; Oxley, D
Data(s)

01/01/1998

Resumo

Self-incompatibility RNases (S-RNases) are an allelic series of style glycoproteins associated with rejection of self-pollen in solanaceous plants. The nucleotide sequences of S-RNase alleles from several genera have been determined, but the structure of the gene products has only been described for those from Nicotiana alata. We report on the N-glycan structures and the disulfide bonding of the S-3-RNase from wild tomato (Lycopersicon peruvianum) and use this and other information to construct a model of this molecule. The S-3-RNase has a single N-glycosylation site (Asn-28) to which one of three N-glycans is attached. S-3-RNase has seven Cys residues; six are involved in disulfide linkages (Cys-16-Cys-21, Cys-46-Cys-91, and Cys-166-Cys-177), and one has a free thiol group (Cys-150). The disulfide-bonding pattern is consistent with that observed in RNase Rh, a related RNase for which radiographic-crystallographic information is available. A molecular model of the S-3-RNase shows that four of the most variable regions of the S-RNases are clustered on one surface of the molecule. This is discussed in the context of recent experiments that set out to determine the regions of the S-RNase important for recognition during the self-incompatibility response.

Identificador

http://espace.library.uq.edu.au/view/UQ:34671

Idioma(s)

eng

Palavras-Chave #Plant Sciences #Linked Glycan Chains #Nicotiana-alata #Lycopersicon-peruvianum #Sequence #Proteins #Ribonucleases #Glycoprotein #Expression #Plants #Gene
Tipo

Journal Article