Reference "Molecular analysis of the gene encoding a rice starch branching enzyme"

Reference ID

1979

Title

Molecular analysis of the gene encoding a rice starch branching enzyme

Source

Molecular & General Genetics, 1993, vol. 237, pp. 10-16

Authors (4)

Kawasaki-T	Mizuno-K
Baba-T	Shimada-H

Abstract

The sequence of a rice gene encoding a starch branching enzyme (sbe1) shows
extreme divergence from that of the rice gene, that is homologous to bacterial
glycogen branching enzyme (sbe2). sbe1 is expressed abundantly and specifically
in developing seeds and maximally in the middle stages of seed development. This
expression pattern completely coincides with that of the waxy gene, which
encodes a granule-bound starch synthase. Three G-box motifs and consensus
promoter sequences are present in the 5' flanking region of sbe1. It encodes a
putative transit peptide, which is required for transport into the amyloplast. A
2.2 kb intron (intron 2) precedes the border between the regions encoding the
transit peptide and the mature protein, and contains a high G/C content with
several repeated sequences in its 5' half. Although only a single copy of sbe1
is present in the rice genome, Southern analysis using intron 2 as a probe
indicates the presence of several homologous sequences in the rice genome,
suggesting that this large intron and also the transit peptide coding region may
be acquired from another portion of the genome by duplication and insertion of
the sequence into the gene.