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18  structures 4628  species 2  interactions 6279  sequences 14  architectures

Family: Bac_DnaA (PF00308)

Summary: Bacterial dnaA protein

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

This is the Wikipedia entry entitled "DnaA". More...

DnaA Edit Wikipedia article

Chromosomal replication initiator protein dnaA
Identifiers
Organism Escherichia coli
(str. K-12 substr. MG1655)
Symbol DnaA
Entrez 948217
RefSeq (Prot) NP_418157.1
UniProt P03004
Other data
Chromosome genome: 3.88 - 3.88 Mb
Bac_DnaA_C
PDB 1j1v EBI.jpg
crystal structure of dnaa domainiv complexed with dnaabox dna
Identifiers
Symbol Bac_DnaA_C
Pfam PF08299
Pfam clan CL0123
InterPro IPR013159
SCOP 1j1v
SUPERFAMILY 1j1v
Bac_DnaA
PDB 2hcb EBI.jpg
structure of amppcp-bound dnaa from aquifex aeolicus
Identifiers
Symbol Bac_DnaA
Pfam PF00308
Pfam clan CL0023
InterPro IPR013317
PROSITE PDOC00771
SCOP 1j1v
SUPERFAMILY 1j1v

DnaA is a protein that activates initiation of DNA replication in prokaryotes.[1] It is a replication initiation factor which promotes the unwinding of DNA at oriC.[1] The onset of the initiation phase of DNA replication is determined by the concentration of DnaA.[1] DnaA accumulates during growth and then triggers the initiation of replication.[1] Replication begins with active DnaA binding to 9-mer (9-bp) repeats upstream of oriC.[1] Binding of DnaA leads to strand separation at the 13-mer repeats.[1] This binding causes the DNA to loop in preparation for melting open by the helicase DnaB.[1]

Function[edit]

The active form DnaA is bound to ATP.[1] Immediately after a cell has divided, the level of active DnaA within the cell is low.[1] Although the active form of DnaA requires ATP, the formation of the oriC/DnaA complex and subsequent DNA unwinding does not require ATP hydrolysis.[2]

The oriC site in E. coli has three AT rich 13 base pair regions (DUEs) followed by four 9 bp regions.[3] Around 10 DnaA molecules bind to the 9 bp regions, which wrap around the proteins causing the DNA at the AT-rich region to unwind. There are 8 DnaA binding sites within oriC, to which DnaA binds with differential affinity. When DNA replication is about to commence, DnaA occupies all of the high and low affinity binding sites. The denatured AT-rich region allows for the recruitment of DnaB (helicase), which complexes with DnaC (helicase loader). DnaC helps the helicase to bind to and to properly accommodate the ssDNA at the 13 bp region; this is accomplished by ATP hydrolysis, after which DnaC is released. Single-strand binding proteins (SSBs) stabilize the single DNA strands in order to maintain the replication bubble. DnaB is a 5'→3' helicase, so it travels on the lagging strand. It associates with DnaG (a primase) to form the only primer for the leading strand and to add RNA primers on the lagging strand. The interaction between DnaG and DnaB is necessary to control the longitude of Okazaki fragments on the lagging strand. DNA polymerase III is then able to start DNA replication.

DnaA contains two conserved regions: the first is located in the central part of the protein and corresponds to the ATP-binding domain, the second is located in the C-terminal half and is involved in DNA-binding.[4]

References[edit]

  1. ^ a b c d e f g h i Foster JB, Slonczewski J (2009). Microbiology: an evolving science. New York: W.W. Norton & Co. ISBN 0-393-97857-5. 
  2. ^ Leonard AC, Grimwade JE (December 2010). "Regulating DnaA complex assembly: it is time to fill the gaps". Curr. Opin. Microbiol. 13 (6): 766–72. doi:10.1016/j.mib.2010.10.001. PMC 3005629. PMID 21035377. 
  3. ^ Fuller RS, Funnell BE, Kornberg A (October 1984). "The dnaA protein complex with the E. coli chromosomal replication origin (oriC) and other DNA sites". Cell 38 (3): 889–900. PMID 6091903. 
  4. ^ Roth A, Messer W (May 1995). "The DNA binding domain of the initiator protein DnaA". EMBO J. 14 (9): 2106–11. PMC 398312. PMID 7744016. 

Further reading[edit]

  • Pratt CA, Voet D, Voet JG (2012). Fundamentals of Biochemistry: Life at the Molecular Level. New York: Wiley. ISBN 0-470-54784-7. 
  • Cox M, Nelson DR (2008). Lehninger Principles of Biochemistry. W H Freeman & Co (Sd). ISBN 1-4292-2416-9. 

External links[edit]

This article incorporates text from the public domain Pfam and InterPro IPR013159

This article incorporates text from the public domain Pfam and InterPro IPR013317

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Bacterial dnaA protein Provide feedback

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Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR013317

This entry represents the central domain of bacterial DnaA proteins [PUBMED:8110826, PUBMED:1779750, PUBMED:2558436] that play an important role in initiating and regulating chromosomal replication. DnaA is an ATP- and DNA-binding protein. It binds specifically to 9 bp nucleotide repeats known as dnaA boxes which are found in the chromosome origin of replication (oriC).

DnaA is a protein of about 50 kDa that contains two conserved regions: the first is located in the N-terminal half and corresponds to the ATP-binding domain, the second is located in the C-terminal half and could be involved in DNA-binding. The protein may also bind the RNA polymerase beta subunit, the dnaB and dnaZ proteins, and the groE gene products (chaperonins) [PUBMED:2172087].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan P-loop_NTPase (CL0023), which has the following description:

AAA family proteins often perform chaperone-like functions that assist in the assembly, operation, or disassembly of protein complexes [2].

The clan contains the following 198 members:

6PF2K AAA AAA-ATPase_like AAA_10 AAA_11 AAA_12 AAA_13 AAA_14 AAA_15 AAA_16 AAA_17 AAA_18 AAA_19 AAA_2 AAA_21 AAA_22 AAA_23 AAA_24 AAA_25 AAA_26 AAA_27 AAA_28 AAA_29 AAA_3 AAA_30 AAA_31 AAA_32 AAA_33 AAA_34 AAA_35 AAA_4 AAA_5 AAA_6 AAA_7 AAA_8 AAA_9 AAA_PrkA ABC_ATPase ABC_tran ABC_tran_2 Adeno_IVa2 Adenylsucc_synt ADK AFG1_ATPase AIG1 APS_kinase Arch_ATPase Arf ArgK ArsA_ATPase ATP-synt_ab ATP_bind_1 ATP_bind_2 Bac_DnaA CbiA CMS1 CoaE CobA_CobO_BtuR CobU cobW CPT CTP_synth_N Cytidylate_kin Cytidylate_kin2 DAP3 DEAD DEAD_2 DLIC DNA_pack_C DNA_pack_N DNA_pol3_delta DNA_pol3_delta2 DnaB_C dNK DUF1253 DUF1611 DUF2075 DUF2478 DUF258 DUF2791 DUF2813 DUF3584 DUF463 DUF815 DUF853 DUF87 DUF927 Dynamin_N Exonuc_V_gamma FeoB_N Fer4_NifH Flavi_DEAD FTHFS FtsK_SpoIIIE G-alpha Gal-3-0_sulfotr GBP GTP_EFTU GTP_EFTU_D2 GTP_EFTU_D4 Gtr1_RagA Guanylate_kin GvpD HDA2-3 Helicase_C Helicase_C_2 Helicase_C_4 Helicase_RecD Herpes_Helicase Herpes_ori_bp Herpes_TK IIGP IPPT IPT IstB_IS21 KaiC KAP_NTPase Kinesin Kinesin-relat_1 Kinesin-related KTI12 LpxK MCM MEDS Mg_chelatase Mg_chelatase_2 MipZ Miro MMR_HSR1 MobB MukB MutS_V Myosin_head NACHT NB-ARC NOG1 NTPase_1 ParA Parvo_NS1 PAXNEB PduV-EutP PhoH PIF1 Podovirus_Gp16 Polyoma_lg_T_C Pox_A32 PPK2 PPV_E1_C PRK Rad17 Rad51 Ras RecA ResIII RHD3 RHSP RNA12 RNA_helicase RuvB_N SbcCD_C SecA_DEAD Septin Sigma54_activ_2 Sigma54_activat SKI SMC_N SNF2_N Spore_IV_A SRP54 SRPRB Sulfotransfer_1 Sulfotransfer_2 Sulfotransfer_3 Sulphotransf T2SE T4SS-DNA_transf Terminase_1 Terminase_3 Terminase_6 Terminase_GpA Thymidylate_kin TIP49 TK TniB Torsin TraG-D_C tRNA_lig_kinase TrwB_AAD_bind UPF0079 UvrD-helicase UvrD_C UvrD_C_2 Viral_helicase1 VirC1 VirE YhjQ Zeta_toxin Zot

Alignments

We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

  Seed
(14)
Full
(6279)
Representative proteomes NCBI
(7863)
Meta
(4434)
RP15
(415)
RP35
(826)
RP55
(1072)
RP75
(1289)
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  Seed
(14)
Full
(6279)
Representative proteomes NCBI
(7863)
Meta
(4434)
RP15
(415)
RP35
(826)
RP55
(1072)
RP75
(1289)
Alignment:
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Order:
Sequence:
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We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(14)
Full
(6279)
Representative proteomes NCBI
(7863)
Meta
(4434)
RP15
(415)
RP35
(826)
RP55
(1072)
RP75
(1289)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Prosite
Previous IDs: bac_dnaA;
Type: Family
Author: Finn RD
Number in seed: 14
Number in full: 6279
Average length of the domain: 203.50 aa
Average identity of full alignment: 39 %
Average coverage of the sequence by the domain: 51.24 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 20.4 20.4
Trusted cut-off 20.4 20.4
Noise cut-off 20.3 20.3
Model length: 219
Family (HMM) version: 13
Download: download the raw HMM for this family

Species distribution

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Interactions

There are 2 interactions for this family. More...

Bac_DnaA_C Bac_DnaA

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Bac_DnaA domain has been found. There are 18 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.

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