home *** CD-ROM | disk | FTP | other *** search
- **********************************************
- * 11-S plant seed storage proteins signature *
- **********************************************
-
- Plant seed storage proteins, whose principal function appears to be the major
- nitrogen source for the developing plant, can be classified, on the basis of
- their structure, into different families. 11-S are non-glycosylated proteins
- which form hexameric structures [1,2]. Each of the subunits in the hexamer is
- itself composed of an acidic and a basic chain derived from a single precursor
- and linked by a disulfide bond. This structure is shown in the following
- representation.
-
- +-------------------------+
- | |
- xxxxxxxxxxxCxxxxxxxxxxxxxxxxxxxxxxNGxCxxxxxxxxxxxxxxxxxxxxxxx
- *********
- <------Acidic-subunit-------------><-----Basic-subunit------>
- <-----------------About-480-to-500-residues----------------->
-
- 'C': conserved cysteine involved in a disulfide bond.
- '*': position of the pattern.
-
- Proteins that belong to the 11-S family are: pea and broad bean legumins, rape
- cruciferin, rice glutelins, cotton beta-globulins, soybean glycinins, pumpkin
- 11-S globulin, oat globulin, sunflower helianthinin G3, etc.
-
- As a signature pattern for this family of proteins we used the region that
- includes the conserved cleavage site between the acidic and basic subunits
- (Asn-Gly) and a proximal cysteine residue which is involved in the interchain
- disulfide bond.
-
- -Consensus pattern: N-G-x-[DE](2)-x-[LIVMF]-C-[ST]-x(11,12)-[PAG]-D
- [C is involved in a disulfide bond]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Hayashi M., Mori H., Nishimura M., Akazawa T., Hara-Nishimura I.
- Eur. J. Biochem. 172:627-632(1988).
- [ 2] Shotwell M.A., Afonso C., Davies E., Chesnut R.S., Larkins B.A.
- Plant Physiol. 87:698-704(1988).
-