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Protein

Terminase, large subunit

Gene

A

Organism
Escherichia phage lambda (Bacteriophage lambda)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Component of the terminase that processes and encapsidates viral genomes during virion assembly. The terminase lies at a unique vertex of the procapsid and is composed of two small subunits involved in viral DNA recognition and one large subunit possessing endonucleolytic and ATPase activities. To initiate packaging, it binds a specific sequence called cos, at the junction of adjacent viral genomes in the concatemeric DNA substrate. Next, in a reaction stimulated by the presence of proheads and ATP but not requiring ATP hydrolysis, the terminase creates two nicks 12bp appart at the cos site, one on each stand. Terminase then separates the cohesive ends in a reaction requiring ATP hydrolysis. The heterotrimer remains bound to the left end of the genome to be packaged, forming a stable DNA-protein complex known as complex I. In a reaction facilitated by a viral assembly catalyst, gpFI, complex I binds a prohead, a preformed head shell precursor, to form complex II. In another packaging reaction requiring ATP hydrolysis, the DNA is translocated into the prohead until the next cos site on the concatemer reaches the packaging complex. At this time the downstream cos site is cut and the heterotrimer undocks from the DNA-filled head to remain bound to the left end of concatemer's next genome. The new heterotrimer-DNA complex I binds another prohead to continue the processive, polarized packaging of viral genomes. The terminase is dependent upon host integration host factor (ihfA/ihfB) for these activities.1 Publication

Catalytic activityi

Endonucleolytic cleavage of DNA to give specific double-stranded fragments with terminal 5'-phosphates.

Cofactori

Mg2+By similarityNote: Binds 2 Mg2+ ions per subunit.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Active sitei179For ATPase activitySequence analysis1
Metal bindingi401Magnesium 1; catalytic; for nuclease activityBy similarity1
Metal bindingi401Magnesium 2; catalytic; for nuclease activityBy similarity1
Metal bindingi476Magnesium 2; catalytic; for nuclease activityBy similarity1
Metal bindingi571Magnesium 1; catalytic; for nuclease activityBy similarity1

GO - Molecular functioni

GO - Biological processi

  • viral DNA genome packaging Source: UniProtKB

Keywordsi

Molecular functionEndonuclease, Hydrolase, Nuclease
Biological processViral genome packaging, Viral release from host cell
LigandMagnesium, Metal-binding

Names & Taxonomyi

Protein namesi
Recommended name:
Terminase, large subunit (EC:3.1.21.4)
Alternative name(s):
DNA-packaging protein A
Large terminase protein
gpA
Gene namesi
Name:A
Ordered Locus Names:lambdap02
OrganismiEscherichia phage lambda (Bacteriophage lambda)
Taxonomic identifieri10710 [NCBI]
Taxonomic lineageiVirusesdsDNA viruses, no RNA stageCaudoviralesSiphoviridaeLambdavirus
Virus hostiEscherichia coli [TaxID: 562]
Proteomesi
  • UP000001711 Componenti: Genome

Subcellular locationi

GO - Cellular componenti

Keywords - Cellular componenti

Host cytoplasm

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000776731 – 641Terminase, large subunitAdd BLAST641

Proteomic databases

PRIDEiP03708

Interactioni

Subunit structurei

Heterotrimer of two small and one large terminase subunits; the terminase is composed of two subunits, a small terminase (ST) subunit involved in viral DNA recognition, and a large terminase (LT) subunit possessing endonucleolytic and ATPase activities. The active complex may be composed of five heterotrimers.1 Publication

Protein-protein interaction databases

IntActiP03708, 10 interactors

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 48Binding to terminase small subunitAdd BLAST48
Regioni604 – 641Prohead bindingAdd BLAST38

Motif

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Motifi76 – 83Walker A motif8
Motifi174 – 179Walker B motif6

Sequence similaritiesi

Phylogenomic databases

KOiK21512
OrthoDBiVOG0900004B

Family and domain databases

InterProiView protein in InterPro
IPR008866 Phage_lambda_GpA
PfamiView protein in Pfam
PF05876 Terminase_GpA, 1 hit

Sequencei

Sequence statusi: Complete.

P03708-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MNISNSQVNR LRHFVRAGLR SLFRPEPQTA VEWADANYYL PKESAYQEGR
60 70 80 90 100
WETLPFQRAI MNAMGSDYIR EVNVVKSARV GYSKMLLGVY AYFIEHKQRN
110 120 130 140 150
TLIWLPTDGD AENFMKTHVE PTIRDIPSLL ALAPWYGKKH RDNTLTMKRF
160 170 180 190 200
TNGRGFWCLG GKAAKNYREK SVDVAGYDEL AAFDDDIEQE GSPTFLGDKR
210 220 230 240 250
IEGSVWPKSI RGSTPKVRGT CQIERAASES PHFMRFHVAC PHCGEEQYLK
260 270 280 290 300
FGDKETPFGL KWTPDDPSSV FYLCEHNACV IRQQELDFTD ARYICEKTGI
310 320 330 340 350
WTRDGILWFS SSGEEIEPPD SVTFHIWTAY SPFTTWVQIV KDWMKTKGDT
360 370 380 390 400
GKRKTFVNTT LGETWEAKIG ERPDAEVMAE RKEHYSAPVP DRVAYLTAGI
410 420 430 440 450
DSQLDRYEMR VWGWGPGEES WLIDRQIIMG RHDDEQTLLR VDEAINKTYT
460 470 480 490 500
RRNGAEMSIS RICWDTGGID PTIVYERSKK HGLFRVIPIK GASVYGKPVA
510 520 530 540 550
SMPRKRNKNG VYLTEIGTDT AKEQIYNRFT LTPEGDEPLP GAVHFPNNPD
560 570 580 590 600
IFDLTEAQQL TAEEQVEKWV DGRKKILWDS KKRRNEALDC FVYALAALRI
610 620 630 640
SISRWQLDLS ALLASLQEED GAATNKKTLA DYARALSGED E
Length:641
Mass (Da):73,302
Last modified:July 21, 1986 - v1
Checksum:i4C5719C9A2D87B7A
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02459 Genomic DNA Translation: AAA96534.1
PIRiD04333 JVBPAL
RefSeqiNP_040581.1, NC_001416.1

Genome annotation databases

GeneIDi2703524
KEGGivg:2703524

Similar proteinsi

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
J02459 Genomic DNA Translation: AAA96534.1
PIRiD04333 JVBPAL
RefSeqiNP_040581.1, NC_001416.1

3D structure databases

ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

IntActiP03708, 10 interactors

Proteomic databases

PRIDEiP03708

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

GeneIDi2703524
KEGGivg:2703524

Phylogenomic databases

KOiK21512
OrthoDBiVOG0900004B

Family and domain databases

InterProiView protein in InterPro
IPR008866 Phage_lambda_GpA
PfamiView protein in Pfam
PF05876 Terminase_GpA, 1 hit
ProtoNetiSearch...

Entry informationi

Entry nameiTERL_LAMBD
AccessioniPrimary (citable) accession number: P03708
Entry historyiIntegrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: September 12, 2018
This is version 80 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

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