Reviewed, UniProtKB/Swiss-Prot P03880 (ANI1_EMENI)

Names and origin

Protein names

Recommended name:
    Intron-encoded DNA endonuclease I-AniI
Alternative name(s):
    mRNA maturase bI1
    COB intron protein
Cleaved into the following 2 chains:
    1- Recommended name:
            Truncated non-functional cytochrome b
    2- Recommended name:
            DNA endonuclease/RNA maturase I-AniI
              EC=3.1.-.-

Gene names

Name:

I-AniI

Encoded on

Mitochondrion

Organism

Emericella nidulans (Aspergillus nidulans)

Taxonomic identifier

162425 [NCBI]

Taxonomic lineage

Eukaryota › Fungi › Dikarya › Ascomycota › Pezizomycotina › Eurotiomycetes › Eurotiomycetidae › Eurotiales › Trichocomaceae › Emericella

Protein attributes

Sequence length	488 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	Mitochondrial DNA endonuclease and mRNA maturase involved in intron homing and required for splicing of the cytochrome b (cobA) gene intron, containing its own coding sequence. The protein stimulates the intrinsic ribozyme activity of the intron through binding to and stabilizing specific secondary and tertiary structure elements in the RNA. As an endonuclease it introduces a specific double-strand break at the junction of the two exons the cobA gene and thus mediates the insertion of an intron, containing its own coding sequence (group I intron), into an intronless gene. Recognizes with limited specificity and cleaves the sequence 5'-GAGGAGGTTTCTCTGTA-3'. The proteins RNA and DNA recognition and binding surfaces are independent. Ref.3 Ref.4 Ref.5
Cofactor	Magnesium.
Subunit structure	Homodimer.
Subcellular location	Mitochondrion.
Post-translational modification	The mature protein may arise from proteolytic cleavage of an in-frame translation of cobA exon 1 plus intron, containing the I-AniI open reading frame. Cleavage may take place close to Met-213 resulting in an active endonuclease/maturase of about 30 kDa By similarity.
Miscellaneous	Residues 237 to 488 are sufficient for endonuclease, intron homing, and RNA maturase activity.
Sequence similarities	In the C-terminal section; belongs to the LAGLIDADG endonuclease family.
Sequence caution	The sequence AAA31737.1 differs from that shown. Reason: Erroneous gene model prediction. The cobA ORF was not predicted to be expressed alternatively as a fusion with intron 4, and intron 4 CDS was not annotated.

Ontologies

Keywords
Biological process	Intron homing mRNA processing mRNA splicing
Cellular component	Mitochondrion
Molecular function	Endonuclease Hydrolase Nuclease
Technical term	3D-structure
Gene Ontology (GO)
Biological process	RNA splicing Inferred from electronic annotation. Source: UniProtKB-KW intron homing Inferred from electronic annotation. Source: UniProtKB-KW mRNA processing Inferred from electronic annotation. Source: UniProtKB-KW respiratory electron transport chain Inferred from electronic annotation. Source: InterPro
Cellular component	membrane Inferred from electronic annotation. Source: InterPro mitochondrion Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	DNA binding Inferred from electronic annotation. Source: InterPro electron carrier activity Inferred from electronic annotation. Source: InterPro endonuclease activity Inferred from electronic annotation. Source: UniProtKB-KW oxidoreductase activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – ?

Truncated non-functional cytochrome b

PRO_0000013491

Chain

? – 488

DNA endonuclease/RNA maturase I-AniI

PRO_0000013492

Regions

Region

1 – 169

169

cobA exon 1 encoded

Region

170 – 488

319

cobA intron encoded

Experimental info

Sequence conflict

295

1

I → R Ref.6

Secondary structure

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488

Helix Strand Turn

Details...

Helix

239 – 250

12

Beta strand

251 – 258

8

Beta strand

261 – 271

11

Helix

272 – 274

3

Helix

275 – 285

11

Beta strand

289 – 293

5

Beta strand

300 – 305

6

Helix

308 – 321

14

Helix

329 – 341

13

Helix

346 – 348

3

Helix

362 – 367

6

Helix

371 – 382

12

Beta strand

384 – 386

3

Beta strand

389 – 394

6

Beta strand

400 – 406

7

Helix

409 – 418

10

Beta strand

429 – 437

9

Helix

440 – 451

12

Beta strand

453 – 455

3

Helix

460 – 474

15

Helix

476 – 479

4

Sequences

	Sequence		Length	Mass (Da)
	P03880-1 [UniParc]. Last modified July 19, 2004. Version 3. Checksum: 40B106A275535E27	FASTA	488	55,395
	10 20 30 40 50 60 MRILKSHPLL KIVNSYIIDS PQPANLSYLW NFGSLLALCL GIQIVTGVTL AMHYTPSVSE 70 80 90 100 110 120 AFNSVEHIMR DVNNGWLVRY LHSNTASAFF FLVYLHIGRG LYYGSYKTPR TLTWAIGTVI 130 140 150 160 170 180 LIVMMATAFL GYVLPYGQMS LWGATVITNL MSAIPWIGQD IVEFIWGGLY TDEPQCGDVL 190 200 210 220 230 240 LKILLNAGKS PILGFAYDLF FIIVLLIGVK IAMTRGKSAG VRSLHTSEAS QRLHAGDLTY 250 260 270 280 290 300 AYLVGLFEGD GYFSITKKGK YLTYELGIEL SIKDVQLIYK IKKILGIGIV SFRKINEIEM 310 320 330 340 350 360 VALRIRDKNH LKSFILPIFE KYPMFSNKQY DYLRFRNALL SGIISLEDLP DYTRSDEPLN 370 380 390 400 410 420 SIESIINTSY FSAWLVGFIE AEGCFSVYKL NKDDDYLIAS FDIAQRDGDI LISAIRKYLS 430 440 450 460 470 480 FTTKVYLDKT NCSKLKVTSV RSVENIIKFL QNAPVKLLGN KKLQYLLWLK QLRKISRYSE KIKIPSNY

References

[1]	"The mosaic organization of the apocytochrome b gene of Aspergillus nidulans revealed by DNA sequencing." Waring R.B., Davies R.W., Lee S., Grisi E., Berks M.M., Scazzocchio C. Cell 27:4-11(1981) [PubMed: 7034966] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Internal structure of a mitochondrial intron of Aspergillus nidulans." Waring R.B., Davies R.W., Scazzocchio C., Brown T.A. Proc. Natl. Acad. Sci. U.S.A. 79:6332-6336(1982) [PubMed: 6755468] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 170-488.
[3]	"A protein encoded by a group I intron in Aspergillus nidulans directly assists RNA splicing and is a DNA endonuclease." Ho Y., Kim S.-J., Waring R.B. Proc. Natl. Acad. Sci. U.S.A. 94:8994-8999(1997) [PubMed: 9256423] [Abstract] Cited for: FUNCTION, RNA SPLICING AND ENDONUCLEASE ACTIVITY.
[4]	"The maturase encoded by a group I intron from Aspergillus nidulans stabilizes RNA tertiary structure and promotes rapid splicing." Ho Y., Waring R.B. J. Mol. Biol. 292:987-1001(1999) [PubMed: 10512698] [Abstract] Cited for: FUNCTION, BIOCHEMICAL CHARACTERIZATION OF MATURASE ACTIVITY.
[5]	"Functionally distinct nucleic acid binding sites for a group I intron encoded RNA maturase/DNA homing endonuclease." Chatterjee P., Brady K.L., Solem A., Ho Y., Caprara M.G. J. Mol. Biol. 329:239-251(2003) [PubMed: 12758073] [Abstract] Cited for: FUNCTION, RNA AND DNA-BINDING.
[6]	"Structural and biochemical analyses of DNA and RNA binding by a bifunctional homing endonuclease and group I intron splicing factor." Bolduc J.M., Spiegel P.C., Chatterjee P., Brady K.L., Downing M.E., Caprara M.G., Waring R.B., Stoddard B.L. Genes Dev. 17:2875-2888(2003) [PubMed: 14633971] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) OF 237-488 IN COMPLEX WITH DNA.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBLGenBankDDBJ

J01388 Genomic DNA. Translation: AAA31737.1. Sequence problems.
J01389 Genomic DNA. No translation available.
J01387 Genomic DNA. No translation available.

PIR

QXASBI. A04513.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1P8K	X-ray	2.60	Z	237-488	[»]
2QOJ	X-ray	2.40	Z	237-488	[»]
3EH8	X-ray	2.70	A/D/G	237-488	[»]

ModBase

Search...

Family and domain databases

InterPro

IPR016175. Cyt_b/b6.
IPR005797. Cyt_b/b6_N.
IPR001982. Endonuc_LAG/HNH.
[Graphical view]

Gene3D

G3DSA:1.20.810.10. Cytochrome_b/b6. 1 hit.

PANTHER

PTHR19271. Cytochrome_b/b6. 1 hit.

Pfam

PF00033. Cytochrom_B_N. 1 hit.
PF00961. LAGLIDADG_1. 2 hits.
[Graphical view]

PROSITE

PS51002. CYTB_NTER. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

ANI1_EMENI

Accession

Primary (citable) accession number: P03880

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	July 19, 2004
Last modified:	June 16, 2009
This is version 65 of the entry and version 3 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

FPAP (Fungal Proteome Annotation Project)