Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

CRISPR system Cascade subunit CasA

Gene

casA

Organism
Escherichia coli (strain K12)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

CRISPR (clustered regularly interspaced short palindromic repeat), is an adaptive immune system that provides protection against mobile genetic elements (viruses, transposable elements and conjugative plasmids). CRISPR clusters contain sequences complementary to antecedent mobile elements and target invading nucleic acids. CRISPR clusters are transcribed and processed into CRISPR RNA (crRNA).
A component of Cascade, which participates in CRISPR interference, the third stage of CRISPR immunity. Cascade binds both crRNA and in a sequence-specific manner negatively supercoiled dsDNA target. This leads to the formation of an R-loop in which the crRNA binds the target DNA, displacing the noncomplementary strand. Cas3 is recruited to Cascade, probably via interactions with CasA, nicks target DNA and then unwinds and cleaves the target, leading to DNA degradation and invader neutralization. CasA is not required for formation of Cascade, but probably enhances binding to and subsequent recognition of both target dsDNA and ssDNA.

GO - Molecular functioni

  • DNA binding Source: EcoCyc
  • RNA binding Source: EcoCyc
  • zinc ion binding Source: EcoCyc

GO - Biological processi

  • defense response to virus Source: EcoCyc
Complete GO annotation...

Keywords - Biological processi

Antiviral defense

Keywords - Ligandi

DNA-binding, RNA-binding

Enzyme and pathway databases

BioCyciEcoCyc:G7430-MONOMER.
ECOL316407:JW2730-MONOMER.
MetaCyc:G7430-MONOMER.

Names & Taxonomyi

Protein namesi
Recommended name:
CRISPR system Cascade subunit CasA
Alternative name(s):
CRISPR type I-E/Ecoli-associated protein CasA/Cse1
CRISPR-associated protein CasA/Cse1
Gene namesi
Name:casA
Synonyms:cse1, ygcL
Ordered Locus Names:b2760, JW2730
OrganismiEscherichia coli (strain K12)
Taxonomic identifieri83333 [NCBI]
Taxonomic lineageiBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia
Proteomesi
  • UP000000318 Componenti: Chromosome
  • UP000000625 Componenti: Chromosome

Organism-specific databases

EcoGeneiEG13119. casA.

Subcellular locationi

GO - Cellular componenti

  • protein complex Source: EcoCyc
Complete GO annotation...

Pathology & Biotechi

Disruption phenotypei

Loss of resistance to bacteriophage lambda infection, loss of plasmid silencing.3 Publications

Mutagenesis

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Mutagenesisi129 – 1291F → A: 80% increase in phage sensitivity; 500-fold decrease in affinity for target dsDNA. 1 Publication
Mutagenesisi130 – 1301V → A: 20% increase in phage sensitivity; no change in binding of target dsDNA. 1 Publication
Mutagenesisi131 – 1311N → A: 45% increase in phage sensitivity; 60-fold decrease in affinity for target dsDNA. 1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Chaini1 – 502502CRISPR system Cascade subunit CasAPRO_0000169324Add
BLAST

Proteomic databases

PaxDbiQ46901.
PRIDEiQ46901.

Expressioni

Inductioni

Repressed by H-NS, activated by LeuO. Activated by the BaeSR two-component regulatory system, possibly due to envelope stress. Part of the casABCDE-ygbT-ygbF operon.4 Publications

Interactioni

Subunit structurei

Part of the Cascade ribonucleoprotein complex, with stoichiometry CasA1,CasB2,CasC6,CasD1,CasE(1)-crRNA1. Interacts directly with the 5' end of crRNA, CasB, CasD and CasE. Binding of target ssRNA or dsDNA causes a conformational change in the Cascade complex; CasA is required for high affinity target DNA binding. Interacts with Cas3 once Cascade has recognized target DNA.5 Publications

Protein-protein interaction databases

BioGridi4260748. 358 interactions.
DIPiDIP-12128N.
IntActiQ46901. 6 interactions.
STRINGi511145.b2760.

Structurei

Secondary structure

1
502
Legend: HelixTurnBeta strand
Show more details
Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Turni3 – 53Combined sources
Beta strandi9 – 135Combined sources
Beta strandi20 – 223Combined sources
Helixi24 – 285Combined sources
Beta strandi34 – 363Combined sources
Helixi41 – 5818Combined sources
Helixi64 – 729Combined sources
Helixi77 – 848Combined sources
Helixi85 – 906Combined sources
Beta strandi92 – 943Combined sources
Helixi114 – 1174Combined sources
Beta strandi121 – 1244Combined sources
Helixi127 – 1304Combined sources
Beta strandi137 – 1393Combined sources
Helixi141 – 15313Combined sources
Beta strandi173 – 1764Combined sources
Helixi181 – 1877Combined sources
Helixi192 – 1987Combined sources
Turni210 – 2123Combined sources
Beta strandi220 – 2223Combined sources
Helixi223 – 2253Combined sources
Helixi228 – 2325Combined sources
Beta strandi237 – 2415Combined sources
Beta strandi247 – 2493Combined sources
Turni251 – 2533Combined sources
Beta strandi256 – 2583Combined sources
Beta strandi264 – 2674Combined sources
Beta strandi272 – 2754Combined sources
Beta strandi280 – 2823Combined sources
Beta strandi284 – 2896Combined sources
Beta strandi292 – 2976Combined sources
Turni308 – 3103Combined sources
Helixi311 – 32111Combined sources
Beta strandi324 – 3263Combined sources
Helixi329 – 3379Combined sources
Beta strandi345 – 3539Combined sources
Beta strandi356 – 3638Combined sources
Helixi369 – 3724Combined sources
Helixi376 – 40530Combined sources
Helixi411 – 4144Combined sources
Helixi415 – 42814Combined sources
Helixi431 – 4377Combined sources
Turni440 – 4423Combined sources
Helixi443 – 46624Combined sources
Helixi467 – 4693Combined sources
Helixi473 – 4753Combined sources
Helixi476 – 49116Combined sources

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
4QYZX-ray3.03A1-502[»]
4TVXX-ray3.24I/U1-502[»]
4U7UX-ray3.00A/M1-502[»]
5CD4X-ray3.20I/U1-502[»]
5H9EX-ray3.21A1-502[»]
5H9FX-ray2.45A1-502[»]
ProteinModelPortaliQ46901.
SMRiQ46901. Positions 1-495.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Phylogenomic databases

eggNOGiENOG4105CYR. Bacteria.
ENOG410XPCD. LUCA.
HOGENOMiHOG000009770.
InParanoidiQ46901.
KOiK19123.
OMAiTPITTFV.

Family and domain databases

CDDicd09669. Cse1_I-E. 1 hit.
InterProiIPR013381. CRISPR-assoc_prot_Cse1.
[Graphical view]
PfamiPF09481. CRISPR_Cse1. 1 hit.
[Graphical view]
TIGRFAMsiTIGR02547. casA_cse1. 1 hit.

Sequencei

Sequence statusi: Complete.

Q46901-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MNLLIDNWIP VRPRNGGKVQ IINLQSLYCS RDQWRLSLPR DDMELAALAL
60 70 80 90 100
LVCIGQIIAP AKDDVEFRHR IMNPLTEDEF QQLIAPWIDM FYLNHAEHPF
110 120 130 140 150
MQTKGVKAND VTPMEKLLAG VSGATNCAFV NQPGQGEALC GGCTAIALFN
160 170 180 190 200
QANQAPGFGG GFKSGLRGGT PVTTFVRGID LRSTVLLNVL TLPRLQKQFP
210 220 230 240 250
NESHTENQPT WIKPIKSNES IPASSIGFVR GLFWQPAHIE LCDPIGIGKC
260 270 280 290 300
SCCGQESNLR YTGFLKEKFT FTVNGLWPHP HSPCLVTVKK GEVEEKFLAF
310 320 330 340 350
TTSAPSWTQI SRVVVDKIIQ NENGNRVAAV VNQFRNIAPQ SPLELIMGGY
360 370 380 390 400
RNNQASILER RHDVLMFNQG WQQYGNVINE IVTVGLGYKT ALRKALYTFA
410 420 430 440 450
EGFKNKDFKG AGVSVHETAE RHFYRQSELL IPDVLANVNF SQADEVIADL
460 470 480 490 500
RDKLHQLCEM LFNQSVAPYA HHPKLISTLA LARATLYKHL RELKPQGGPS

NG
Length:502
Mass (Da):55,901
Last modified:November 1, 1996 - v1
Checksum:iB3ACC755ABE8D965
GO

Mass spectrometryi

Molecular mass is 55972.4±14.8 Da from positions 1 - 502. 1 Publication

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U29579 Genomic DNA. Translation: AAA69270.1.
U00096 Genomic DNA. Translation: AAC75802.1.
AP009048 Genomic DNA. Translation: BAE76837.1.
PIRiD65057.
RefSeqiNP_417240.1. NC_000913.3.
WP_001050401.1. NZ_LN832404.1.

Genome annotation databases

EnsemblBacteriaiAAC75802; AAC75802; b2760.
BAE76837; BAE76837; BAE76837.
GeneIDi947222.
KEGGiecj:JW2730.
eco:b2760.
PATRICi32120930. VBIEscCol129921_2857.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U29579 Genomic DNA. Translation: AAA69270.1.
U00096 Genomic DNA. Translation: AAC75802.1.
AP009048 Genomic DNA. Translation: BAE76837.1.
PIRiD65057.
RefSeqiNP_417240.1. NC_000913.3.
WP_001050401.1. NZ_LN832404.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
EntryMethodResolution (Å)ChainPositionsPDBsum
4QYZX-ray3.03A1-502[»]
4TVXX-ray3.24I/U1-502[»]
4U7UX-ray3.00A/M1-502[»]
5CD4X-ray3.20I/U1-502[»]
5H9EX-ray3.21A1-502[»]
5H9FX-ray2.45A1-502[»]
ProteinModelPortaliQ46901.
SMRiQ46901. Positions 1-495.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi4260748. 358 interactions.
DIPiDIP-12128N.
IntActiQ46901. 6 interactions.
STRINGi511145.b2760.

Proteomic databases

PaxDbiQ46901.
PRIDEiQ46901.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsemblBacteriaiAAC75802; AAC75802; b2760.
BAE76837; BAE76837; BAE76837.
GeneIDi947222.
KEGGiecj:JW2730.
eco:b2760.
PATRICi32120930. VBIEscCol129921_2857.

Organism-specific databases

EchoBASEiEB2920.
EcoGeneiEG13119. casA.

Phylogenomic databases

eggNOGiENOG4105CYR. Bacteria.
ENOG410XPCD. LUCA.
HOGENOMiHOG000009770.
InParanoidiQ46901.
KOiK19123.
OMAiTPITTFV.

Enzyme and pathway databases

BioCyciEcoCyc:G7430-MONOMER.
ECOL316407:JW2730-MONOMER.
MetaCyc:G7430-MONOMER.

Miscellaneous databases

PROiQ46901.

Family and domain databases

CDDicd09669. Cse1_I-E. 1 hit.
InterProiIPR013381. CRISPR-assoc_prot_Cse1.
[Graphical view]
PfamiPF09481. CRISPR_Cse1. 1 hit.
[Graphical view]
TIGRFAMsiTIGR02547. casA_cse1. 1 hit.
ProtoNetiSearch...

Entry informationi

Entry nameiCSE1_ECOLI
AccessioniPrimary (citable) accession number: Q46901
Secondary accession number(s): Q2MA69
Entry historyi
Integrated into UniProtKB/Swiss-Prot: December 1, 2000
Last sequence update: November 1, 1996
Last modified: September 7, 2016
This is version 95 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Complete proteome, Reference proteome

Documents

  1. Escherichia coli
    Escherichia coli (strain K12): entries and cross-references to EcoGene
  2. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  3. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.