Premium
Identification of regions in which positive selection may operate in S‐RNase of Rosaceae: Implication for S ‐allele‐specific recognition sites in S‐RNase
Author(s) -
Ishimizu Takeshi,
Endo Toshinori,
Yamaguchi-Kabata Yumi,
Nakamura Kazuo T.,
Sakiyama Fumio,
Norioka Shigemi
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01470-7
Subject(s) - rnase p , biology , genetics , ribonuclease , allele , sequence (biology) , evolutionary biology , gene , rna
A stylar S‐RNase is associated with gametophytic self‐incompatibility in the Rosaceae, Solanaceae, and Scrophulariaceae. This S‐RNase is responsible for S ‐allele‐specific recognition in the self‐incompatible reaction, but how it functions in specific discrimination is not clear. Window analysis of the numbers of synonymous ( d S ) and non‐synonymous ( d N ) substitutions in rosaceous S‐RNases detected four regions with an excess of d N over d S in which positive selection may operate (PS regions). The topology of the secondary structure of the S‐RNases predicted by the PHD method is very similar to that of fungal RNase Rh whose tertiary structure is known. When the sequences of S‐RNases are aligned with the sequence of RNase Rh based on the predicted secondary structures, the four PS regions correspond to two surface sites on the tertiary structure of RNase Rh. These findings suggest that in S‐RNases the PS regions also form two sites and are candidates for the recognition sites for S ‐allele‐specific discrimination.