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Q9SE35 (SIL1_CYLFU) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 46. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Silaffin-1
Alternative name(s):
natSil-1

Cleaved into the following 3 chains:

  1. Silaffin-1B
  2. Silaffin-1A2
  3. Silaffin-1A1
Gene names
Name:SIL1
OrganismCylindrotheca fusiformis (Marine diatom)
Taxonomic identifier2853 [NCBI]
Taxonomic lineageEukaryotaStramenopilesBacillariophytaBacillariophyceaeBacillariophycidaeBacillarialesBacillariaceaeCylindrotheca

Protein attributes

Sequence length265 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Catalyzes the polymerization of silica spheres from a silicilic acid solution. It therefore plays a central role in the formation of silica cell wall of diatoms. Ref.1 Ref.3 Ref.4

Subunit structure

Silaffin-1A peptides form large aggregates via electrostatic interactions due to intermolecular interactions between the negatively charged phosphate groups and the polyamine moities. Ref.4

Domain

It is unknown whether the acidic chain located at the N-terminus is functional or whether it represents a propeptide.

Post-translational modification

N6-polymethylaminopropylated. Two lysine residues of each peptide bears 6 to 11 repeats of methyl-propylamine, which gives a possible template for nucleation, and may also control the silica colloid size within the silica deposition vesicle (SDV).

Phosphorylated. All serine residues of the Silaffin-1A1 peptide are phosphorylated. Only minor amounts of the Silaffin-1A2 peptide are phosphorylated. Phosphorylation is essential for the activity. It may represent a source of anions required for silica formation of diatoms. Ref.4

Biotechnological use

Due to its ability to synthesize simple silica nanospheres in vitro from silanes at nearly neutral pH and at ambient temperatures and pressures, it is of great interest in nanotechnology. May be of practical use for the fabrication of photonic devices. Ref.5 Ref.6

Miscellaneous

The results of the mass spectrometry differ for the same peptide due to the length of the methyl-propylamine chains that vary from 14 to 18 units for the Silaffin-1A2 peptide (141-158) and from 13 to 17 units for the Silaffin-1A1 peptide (163-177).

The species-specific pattern of biosilica pattern of diatoms may be generated by polyamines of different chain lengths as well as by a synergistic action of long-chain polyamines and silaffins.

Mass spectrometry

Molecular mass is 2485.7 Da from positions 163 - 177. Determined by ESI. Ref.2

Molecular mass is 2557.1±71.4 Da from positions 163 - 177. Determined by ESI. Ref.2

Molecular mass is 2628.2±71.1 Da from positions 163 - 177. Determined by ESI. Ref.2

Molecular mass is 2699.3±71.1 Da from positions 163 - 177. Determined by ESI. Ref.2

Molecular mass is 2770.4±71.1 Da from positions 163 - 177. Determined by ESI. Ref.2

Molecular mass is 2878.3 Da from positions 141 - 158. Determined by ESI. Ref.2

Molecular mass is 2949.4±71.1 Da from positions 141 - 158. Determined by ESI. Ref.2

Molecular mass is 3020.8±71.4 Da from positions 141 - 158. Determined by ESI. Ref.2

Molecular mass is 3091.8±71 Da from positions 141 - 158. Determined by ESI. Ref.2

Molecular mass is 3162.9±71.1 Da from positions 141 - 158. Determined by ESI. Ref.2

Ontologies

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 1919 Potential
Propeptide20 – 10788Acidic
PRO_0000032597
Peptide108 – 13629Silaffin-1B Probable
PRO_0000032598
Propeptide137 – 1404 Probable
PRO_0000032599
Peptide141 – 15818Silaffin-1A2 Ref.2
PRO_0000032600
Propeptide159 – 1624 Probable
PRO_0000032601
Peptide163 – 17715Silaffin-1A1
PRO_0000032602
Propeptide178 – 1814 Probable
PRO_0000032603
Peptide182 – 19615Silaffin-1A1
PRO_0000032604
Propeptide197 – 2004 Probable
PRO_0000032605
Peptide201 – 21515Silaffin-1A1
PRO_0000032606
Propeptide216 – 2194 Probable
PRO_0000032607
Peptide220 – 23415Silaffin-1A1
PRO_0000032608
Propeptide235 – 2384 Probable
PRO_0000032609
Peptide239 – 25315Silaffin-1A1
PRO_0000032610
Propeptide254 – 26512 Probable
PRO_0000032611

Regions

Repeat108 – 14033R1; atypical
Repeat141 – 16222R2; atypical
Repeat163 – 18119R3
Repeat182 – 20019R4
Repeat201 – 21919R5
Repeat220 – 23819R6
Repeat239 – 25719R7
Region108 – 2571507 X 19 AA repeat of S-S-K-K-S-G-S-Y-S-G-S-K-G-S-K-R-R-[IL]-L

Amino acid modifications

Modified residue1101N6-poly(methylaminopropyl)lysine Probable
Modified residue1111N6,N6-dimethyllysine Probable
Modified residue1431N6-poly(methylaminopropyl)lysine Ref.1
Modified residue1441N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue1541N6-poly(methylaminopropyl)lysine
Modified residue1551N6,N6-dimethyllysine Ref.2
Modified residue1631Phosphoserine Ref.4
Modified residue1641Phosphoserine Ref.4
Modified residue1651N6-poly(methylaminopropyl)lysine Ref.1
Modified residue1661N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue1671Phosphoserine Ref.4
Modified residue1691Phosphoserine Ref.4
Modified residue1711Phosphoserine Ref.4
Modified residue1731Phosphoserine Ref.4
Modified residue1741N6,N6,N6-trimethyl-5-hydroxylysine
Modified residue1761Phosphoserine Ref.4
Modified residue1771N6-poly(methylaminopropyl)lysine
Modified residue1821Phosphoserine Ref.4
Modified residue1831Phosphoserine Ref.4
Modified residue1841N6-poly(methylaminopropyl)lysine Ref.1
Modified residue1851N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue1861Phosphoserine Ref.4
Modified residue1881Phosphoserine Ref.4
Modified residue1901Phosphoserine Ref.4
Modified residue1921Phosphoserine Ref.4
Modified residue1931N6,N6,N6-trimethyl-5-hydroxylysine
Modified residue1951Phosphoserine Ref.4
Modified residue1961N6-poly(methylaminopropyl)lysine
Modified residue2011Phosphoserine Ref.4
Modified residue2021Phosphoserine Ref.4
Modified residue2031N6-poly(methylaminopropyl)lysine Ref.1
Modified residue2041N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue2051Phosphoserine Ref.4
Modified residue2071Phosphoserine Ref.4
Modified residue2091Phosphoserine Ref.4
Modified residue2111Phosphoserine Ref.4
Modified residue2121N6,N6,N6-trimethyl-5-hydroxylysine
Modified residue2141Phosphoserine Ref.4
Modified residue2151N6-poly(methylaminopropyl)lysine
Modified residue2201Phosphoserine Ref.4
Modified residue2211Phosphoserine Ref.4
Modified residue2221N6-poly(methylaminopropyl)lysine Ref.1
Modified residue2231N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue2241Phosphoserine Ref.4
Modified residue2261Phosphoserine Ref.4
Modified residue2281Phosphoserine Ref.4
Modified residue2301Phosphoserine Ref.4
Modified residue2311N6,N6,N6-trimethyl-5-hydroxylysine
Modified residue2331Phosphoserine Ref.4
Modified residue2341N6-poly(methylaminopropyl)lysine
Modified residue2391Phosphoserine Ref.4
Modified residue2401Phosphoserine Ref.4
Modified residue2411N6-poly(methylaminopropyl)lysine Ref.1
Modified residue2421N6,N6-dimethyllysine Ref.1 Ref.2
Modified residue2431Phosphoserine Ref.4
Modified residue2451Phosphoserine Ref.4
Modified residue2471Phosphoserine Ref.4
Modified residue2491Phosphoserine Ref.4
Modified residue2501N6,N6,N6-trimethyl-5-hydroxylysine
Modified residue2521Phosphoserine Ref.4
Modified residue2531N6-poly(methylaminopropyl)lysine

Sequences

Sequence LengthMass (Da)Tools
Q9SE35 [UniParc].

Last modified May 1, 2000. Version 1.
Checksum: E628FAF40E1B051B

FASTA26527,500
        10         20         30         40         50         60 
MKLTAIFPLL FTAVGYCAAQ SIADLAAANL STEDSKSAQL ISADSSDDAS DSSVESVDAA 

        70         80         90        100        110        120 
SSDVSGSSVE SVDVSGSSLE SVDVSGSSLE SVDDSSEDSE EEELRILSSK KSGSYYSYGT 

       130        140        150        160        170        180 
KKSGSYSGYS TKKSASRRIL SSKKSGSYSG YSTKKSGSRR ILSSKKSGSY SGSKGSKRRI 

       190        200        210        220        230        240 
LSSKKSGSYS GSKGSKRRNL SSKKSGSYSG SKGSKRRILS SKKSGSYSGS KGSKRRNLSS 

       250        260 
KKSGSYSGSK GSKRRILSGG LRGSM 

« Hide

References

[1]"Polycationic peptides from diatom biosilica that direct silica nanosphere formation."
Kroeger N., Deutzmann R., Sumper M.
Science 286:1129-1132(1999) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 108-120; 141-151 AND 163-173, FUNCTION, METHYLATION AT LYS-144 AND LYS-166, METHYLAMINOPROPYLATION AT LYS-143 AND LYS-165.
[2]"Silica-precipitating peptides from diatoms. The chemical structure of silaffin-A from Cylindrotheca fusiformis."
Kroeger N., Deutzmann R., Sumper M.
J. Biol. Chem. 276:26066-26070(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE OF 141-158 AND 163-177, MASS SPECTROMETRY, METHYLATION AT LYS-111; LYS-144; LYS-155; LYS-166; LYS-185; LYS-204; LYS-223 AND LYS-242, METHYLAMINOPROPYLATION AT LYS-110; LYS-143; LYS-154; LYS-165; LYS-177; LYS-184; LYS-196; LYS-203; LYS-215; LYS-222; LYS-234; LYS-241 AND LYS-253, METHYLHYDROXYLATION AT LYS-174; LYS-193; LYS-212; LYS-231 AND LYS-250.
[3]"Species-specific polyamines from diatoms control silica morphology."
Kroeger N., Deutzmann R., Bergsdorf C., Sumper M.
Proc. Natl. Acad. Sci. U.S.A. 97:14133-14138(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION.
[4]"Self-assembly of highly phosphorylated silaffins and their function in biosilica morphogenesis."
Kroeger N., Lorenz S., Brunner E., Sumper M.
Science 298:584-586(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: FUNCTION, SUBUNIT, PHOSPHORYLATION AT SER-163; SER-164; SER-167; SER-169; SER-171; SER-173; SER-176; SER-182; SER-183; SER-186; SER-188; SER-190; SER-192; SER-195; SER-201; SER-202; SER-205; SER-207; SER-209; SER-211; SER-214; SER-220; SER-221; SER-224; SER-226; SER-228; SER-230; SER-233; SER-239; SER-240; SER-243; SER-245; SER-247; SER-249 AND SER-252, METHYLHYDROXYLATION AT LYS-174; LYS-193; LYS-212; LYS-231 AND LYS-250.
[5]"Ultrafast holographic nanopatterning of biocatalytically formed silica."
Brott L.L., Naik R.R., Pikas D.J., Kirkpatrick S.M., Tomlin D.W., Whitlock P.W., Clarson S.J., Stone M.O.
Nature 413:291-293(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: BIOTECHNOLOGICAL RELEVANCE.
[6]"Enzyme immobilization in a biomimetic silica support."
Luckarift H.R., Spain J.C., Naik R.R., Stone M.O.
Nat. Biotechnol. 22:211-213(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: BIOTECHNOLOGICAL RELEVANCE.

Web resources

Protein Spotlight

Miniature masonry - Issue 43 of February 2004

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF191634 Genomic DNA. Translation: AAF16940.1.
PIRA59141.

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

ProtoNetSearch...

Entry information

Entry nameSIL1_CYLFU
AccessionPrimary (citable) accession number: Q9SE35
Entry history
Integrated into UniProtKB/Swiss-Prot: February 16, 2004
Last sequence update: May 1, 2000
Last modified: February 19, 2014
This is version 46 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)

Relevant documents

Protein Spotlight

Protein Spotlight articles and cited UniProtKB/Swiss-Prot entries