P07112 (MOBA2_ECOLX) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Mobilization protein A

Alternative name(s):
DNA strand transferase

Including the following 2 domains:

1. DNA relaxase
   EC=5.99.1.2
   Alternative name(s):
   DNA nickase
2. DNA primase
   EC=2.7.7.-

Gene names

Name:	mobA
Synonyms:	repB

Encoded on

Plasmid IncQ RSF1010 Ref.1 Ref.2 Ref.3 Ref.4 Ref.5
Plasmid R1162 Ref.6 Ref.7 Ref.8 Ref.9 Ref.10 Ref.11

Organism

Escherichia coli

Taxonomic identifier

562 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	709 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Part of the relaxosome complex that is responsible for plasmid transfer during conjugation. Locally unwinds DNA and catalyzes the cleavage of one of the DNA strands at oriT. The cleaved strand is then transferred through the dedicated type IV secretion apparatus. MobA remains covalently linked at the 5' end of the strand, and once in the recipient cell, it probably catalyzes the rejoining of the two ends of the strand, re-forming the circular plasmid DNA. The primase activity of mobA is essential for the synthesis of primers that will initiate the DNA replication events necessary to form the double-stranded plasmid in the recipient cell. Ref.5 Ref.7
Catalytic activity	ATP-independent breakage of single-stranded DNA, followed by passage and rejoining.
Cofactor	Divalent metal cation. Can use Mg2+, and to a lesser extent, Mn2+, Ca2+ or Ba2+. Ref.4 Ref.5
Subunit structure	Interacts with mobB and mobC to form the relaxosome.
Subcellular location	Cytoplasm Probable.
Sequence similarities	Belongs to the mobA/mobL family.

Ontologies

Keywords
Biological process	Conjugation Transcription
Cellular component	Cytoplasm DNA-directed RNA polymerase
Domain	Coiled coil
Ligand	Calcium DNA-binding Magnesium Manganese Metal-binding
Molecular function	Isomerase Mobility protein Topoisomerase Transferase
Technical term	3D-structure Direct protein sequencing Multifunctional enzyme Plasmid
Gene Ontology (GO)
Biological process	unidirectional conjugation Inferred from electronic annotation. Source: InterPro
Cellular component	cytoplasm Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	DNA topoisomerase type I activity Inferred from electronic annotation. Source: EC DNA-directed RNA polymerase activity Inferred from electronic annotation. Source: UniProtKB-KW metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Binary interactions

With	Entry	#Exp.	IntAct	Notes
rplV	P61175	1	EBI-554383,EBI-542255	From a different organism.

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Initiator methionine

1

1

Removed Ref.4

Chain

2 – 709

708

Mobilization protein A

PRO_0000210849

Regions

Region

2 – 186

185

DNA relaxase

Region

315 – 709

395

DNA primase

Coiled coil

567 – 594

28

Potential

Sites

Active site

25

1

O-(5'-phospho-DNA)-tyrosine intermediate; for relaxase activity

Metal binding

112

1

Divalent metal cation

Metal binding

120

1

Divalent metal cation

Metal binding

122

1

Divalent metal cation

Site

70

1

Involved in DNA binding Probable

Experimental info

Mutagenesis

25

1

Y → F: 99.5% decrease in conjugal transfer frequency. Ref.11

Mutagenesis

32

1

Y → F: No decrease in conjugal transfer frequency. Ref.11

Mutagenesis

38

1

E → A: No decrease in conjugal transfer frequency. Ref.11

Mutagenesis

74

1

E → A: 50% decrease in conjugal transfer frequency. 10-fold decrease in conjugal transfer frequency and great reduction in the rate of DNA cleavage; when associated with A-76. Ref.11

Mutagenesis

74

1

E → Q: 70% decrease in conjugal transfer frequency. Ref.11

Mutagenesis

76

1

E → A: No decrease in conjugal transfer frequency. 10-fold decrease in conjugal transfer frequency and great reduction in the rate of DNA cleavage; when associated with A-74. Ref.11

Sequence conflict

291

1

P → Q in AAB22064. Ref.3

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

709

Helix Strand Turn

Details...

Beta strand

6 – 9

4

Helix

19 – 27

9

Helix

32 – 34

3

Beta strand

39 – 43

5

Helix

54 – 64

11

Beta strand

73 – 78

6

Helix

85 – 99

15

Beta strand

107 – 112

6

Beta strand

120 – 125

6

Helix

137 – 140

4

Helix

165 – 182

18

Sequences

	Sequence		Length	Mass (Da)
	P07112 [UniParc]. Last modified January 23, 2007. Version 4. Checksum: DDEACDC3CA53D3E1	FASTA	709	77,952
	10 20 30 40 50 60 MAIYHLTAKT GSRSGGQSAR AKADYIQREG KYARDMDEVL HAESGHMPEF VERPADYWDA 70 80 90 100 110 120 ADLYERANGR LFKEVEFALP VELTLDQQKA LASEFAQHLT GAERLPYTLA IHAGGGENPH 130 140 150 160 170 180 CHLMISERIN DGIERPAAQW FKRYNGKTPE KGGAQKTEAL KPKAWLEQTR EAWADHANRA 190 200 210 220 230 240 LERAGHDARI DHRTLEAQGI ERLPGVHLGP NVVEMEGRGI RTDRADVALN IDTANAQIID 250 260 270 280 290 300 LQEYREAIDH ERNRQSEEIQ RHQRVSGADR TAGPEHGDTG RRSPAGHEPD PAGQRGAGGG 310 320 330 340 350 360 VAESPAPDRG GMGGAGQRVA GGSRRGEQRR AERPERVAGV ALEAMANRDA GFHDAYGGAA 370 380 390 400 410 420 DRIVALARPD ATDNRGRLDL AALGGPMKND RTLQAIGRQL KAMGCERFDI GVRDATTGQM 430 440 450 460 470 480 MNREWSAAEV LQNTPWLKRM NAQGNDVYIR PAEQERHGLV LVDDLSEFDL DDMKAEGREP 490 500 510 520 530 540 ALVVETSPKN YQAWVKVADA AGGELRGQIA RTLASEYDAD PASADSRHYG RLAGFTNRKD 550 560 570 580 590 600 KHTTRAGYQP WVLLRESKGK TATAGPALVQ QAGQQIEQAQ RQQEKARRLA SLELPERQLS 610 620 630 640 650 660 RHRRTALDEY RSEMAGLVKR FGDDLSKCDF IAAQKLASRG RSAEEIGKAM AEASPALAER 670 680 690 700 KPGHEADYIE RTVSKVMGLP SVQLARAELA RAPAPRQRGM DRGGPDFSM

References

[1]	"Complete nucleotide sequence and gene organization of the broad-host-range plasmid RSF1010." Scholz P., Haring V., Wittmann-Liebold B., Ashman K., Bagdasarian M., Scherzinger E. Gene 75:271-288(1989) [PubMed: 2653965] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Mobilization of the non-conjugative plasmid RSF1010: a genetic and DNA sequence analysis of the mobilization region." Derbyshire K.M., Hatfull G., Willetts N. Mol. Gen. Genet. 206:161-168(1987) [PubMed: 3033438] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-407.
[3]	"Replication and copy number control of the broad-host-range plasmid RSF1010." Frey J., Bagdasarian M.M., Bagdasarian M. Gene 113:101-106(1992) [PubMed: 1563624] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-400.
[4]	"Purification of the large mobilization protein of plasmid RSF1010 and characterization of its site-specific DNA-cleaving/DNA-joining activity." Scherzinger E., Kruft V., Otto S. Eur. J. Biochem. 217:929-938(1993) [PubMed: 8223650] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-15 AND 23-31, COFACTOR.
[5]	"In vitro cleavage of double- and single-stranded DNA by plasmid RSF1010-encoded mobilization proteins." Scherzinger E., Lurz R., Otto S., Dobrinski B. Nucleic Acids Res. 20:41-48(1992) [PubMed: 1738602] [Abstract] Cited for: FUNCTION IN DNA CLEAVAGE, COFACTOR.
[6]	"Specific binding of MobA, a plasmid-encoded protein involved in the initiation and termination of conjugal DNA transfer, to single-stranded oriT DNA." Bhattacharjee M.K., Meyer R.J. Nucleic Acids Res. 21:4563-4568(1993) [PubMed: 8233790] [Abstract] Cited for: BINDING TO SINGLE-STRANDED ORIT.
[7]	"The primase of broad-host-range plasmid R1162 is active in conjugal transfer." Henderson D., Meyer R.J. J. Bacteriol. 178:6888-6894(1996) [PubMed: 8955311] [Abstract] Cited for: FUNCTION OF PRIMASE DOMAIN IN CONJUGAL TRANSFER.
[8]	"The MobA-linked primase is the only replication protein of R1162 required for conjugal mobilization." Henderson D., Meyer R. J. Bacteriol. 181:2973-2978(1999) [PubMed: 10217797] [Abstract] Cited for: PRIMASE ACTIVITY.
[9]	"MobA, the DNA strand transferase of plasmid R1162: the minimal domain required for DNA processing at the origin of transfer." Becker E.C., Meyer R.J. J. Biol. Chem. 277:14575-14580(2002) [PubMed: 11839744] [Abstract] Cited for: TRANSFERASE ACTIVITY.
[10]	"Relaxed specificity of the R1162 nickase: a model for evolution of a system for conjugative mobilization of plasmids." Becker E.C., Meyer R.J. J. Bacteriol. 185:3538-3546(2003) [PubMed: 12775691] [Abstract] Cited for: SPECIFICITY OF DNA SEQUENCE FOR CLEAVAGE.
[11]	"The structure of the minimal relaxase domain of MobA at 2.1 A resolution." Monzingo A.F., Ozburn A., Xia S., Meyer R.J., Robertus J.D. J. Mol. Biol. 366:165-178(2007) [PubMed: 17157875] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) OF 2-186 IN COMPLEX WITH MANGANESE, REACTION MECHANISM, MUTAGENESIS OF TYR-25; TYR-32; GLU-38; GLU-74 AND GLU-76.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

M28829 Genomic DNA. Translation: AAA26445.1.
X04830 Genomic DNA. Translation: CAA28520.1.
S96966 Genomic DNA. Translation: AAB22064.1.

PIR

JH0126.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2NS6	X-ray	2.10	A	2-186	[»]

ProteinModelPortal

P07112.

SMR

P07112. Positions 2-186.

ModBase

Search...

Protein-protein interaction databases

IntAct

P07112. 1 interaction.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Phylogenomic databases

ProtClustDB

CLSK539302.

Family and domain databases

InterPro

IPR005053. MobA_MobL.
[Graphical view]

Pfam

PF03389. MobA_MobL. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

MOBA2_ECOLX

Accession

Primary (citable) accession number: P07112
Secondary accession number(s): Q60198

Entry history

Integrated into UniProtKB/Swiss-Prot:	April 1, 1988
Last sequence update:	January 23, 2007
Last modified:	October 19, 2011
This is version 64 of the entry and version 4 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program