PROSITE documentation PDOC00283
Bacterial ice-nucleation proteins octamer repeat


Some Gram-negative bacteria express proteins that enable them to promote the nucleation of ice at relatively high temperature (above -5 degree Celsius) [1,2,3]. These proteins are localized at the surface of the outer membrane of the bacteria and can cause frost injury to many plant species. The primary structure of these ice-nucleation proteins is highly repetitive. A central repetitive domain represents about 80% of the total sequence. This domain is mainly formed by the repetition of a conserved region of forty eight residues (48-mer). The 48-mers are themselves composed of three blocks of 16 residues (16-mer). The first eight residues of each of these 16-mers are identical. It has been proposed that the repetitive domain may be directly responsible for aligning water molecules in the seed crystal.

Schematic structure of a 48-mer region:

             /              / |              | \              \
            AGYGSTxTagxxssli  AGYGSTxTagxxsxlt  AGYGSTxTaqxxsxlt
            [16.residues...]  [16.residues...]  [16.residues...]
Last update:

June 1994 / Text revised.


Technical section

PROSITE method (with tools and information) covered by this documentation:

ICE_NUCLEATION, PS00314; Bacterial ice-nucleation proteins octamer repeat  (PATTERN)


1AuthorsWolber P. Warren G.
TitleBacterial ice-nucleation proteins.
SourceTrends Biochem. Sci. 14:179-182(1989).
PubMed ID2672438

2AuthorsWolber P.K.
SourceAdv. Microb. Physiol. 34:205-237(1992).

3AuthorsGurian-Sherman D. Lindow S.E.
SourceFASEB J. 7:1338-1343(1993).

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