 |
|
Annotation rule MF_01032 |
General rule information
[?]
Accession |
MF_01032 |
Dates |
10-SEP-2002 (Created) 19-NOV-2019 (Last updated, Version 30) |
Propagated annotation
[?]
Identifier, protein and gene names
[?]
case <FTTag:HACNmotif>
Protein name |
RecName:
|
Full=Methanogen homoaconitase small subunit;
|
|
Short=HACN;
|
|
EC 4.2.1.114;
|
AltName:
|
Full=Homoaconitate hydratase;
|
|
else
Protein name |
RecName:
|
Full=3-isopropylmalate dehydratase small subunit;
|
|
EC 4.2.1.33;
|
AltName:
|
Full=Alpha-IPM isomerase;
|
|
Short=IPMI;
|
AltName:
|
Full=Isopropylmalate isomerase;
|
|
end case
case <FTTag:HACNmotif>
Function |
Hydro-lyase with broad substrate specificity for cis-unsaturated tricarboxylic acids. Catalyzes both the reversible dehydration of (R)-homocitrate ((R)-2-hydroxybutane-1,2,4-tricarboxylate) to produce cis-homoaconitate ((Z)-but-1-ene-1,2,4-tricarboxylate), and its hydration to homoisocitrate ((1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate). Is also able to hydrate the analogous longer chain substrates cis-homo(2)-aconitate, cis-homo(3)-aconitate. All these reactions are part of the biosynthesis pathway of coenzyme B. |
Catalytic activity |
RHEA:32303: (2R)-homocitrate = (1R,2S)-homoisocitrate
EC 4.2.1.114
|
Pathway |
Organic acid metabolism; 2-oxosuberate biosynthesis. |
Subunit |
Heterotetramer of 2 HacA and 2 HacB proteins. |
else
Function |
Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate. |
Catalytic activity |
RHEA:32287: (2R,3S)-3-isopropylmalate = (2S)-2-isopropylmalate
EC 4.2.1.33
|
Pathway |
Amino-acid biosynthesis; L-leucine biosynthesis; L-leucine from 3-methyl-2-oxobutanoate: step 2/4. |
Subunit |
Heterodimer of LeuC and LeuD. |
end case
Similarity |
Belongs to the LeuD family. LeuD type 2 subfamily. |
case not <FTTag:HACNmotif>
end case
case <FTTag:HACNmotif>
GO:0004409; Molecular function: homoaconitate hydratase activity.
GO:0019298; Biological process: coenzyme B biosynthetic process.
else
GO:0003861; Molecular function: 3-isopropylmalate dehydratase activity.
GO:0009098; Biological process: leucine biosynthetic process.
end case
case <OC:Methanobacteria> or <OC:Methanococci> or <OC:Methanomicrobia> or <OC:Methanopyri>
From: HACB_METJA (Q58667) |
Key
|
|
From
|
|
To
|
|
Description
|
|
Tag
|
|
Condition
|
|
FTGroup
|
MOTIF (Optional)
|
|
24
|
|
27
|
|
YLRT
|
|
HACNmotif
|
|
Y-L-R-T
|
|
|
SITE (Optional)
|
|
26
|
|
26
|
|
Critical for substrate specificity
|
|
|
|
R
|
|
|
end case
Additional information
[?]
Size range |
161-208 amino acids |
Related rules |
MF_01031 (LEUD) |
Fusion |
None |
Comments |
The family member in THET2 is shown to function as a homoaconitase (for lysine biosynthesis), as well as one of the 2 copies found in METJA that catalyzes both the dehydration of (R)-homocitrate and the hydration of cis-homoaconitate for coenzyme B biosynthesis. The other copy in METJA functions both in leucine and isoleucine biosynthesis, since it catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate and between 2-methylmalate and 3-methylmalate. In Archaea, a motif that indicates the protein specificity has been determined (see PubMed=20170198): the presence of the YLRT motif likely indicates HACN activity, while proteins with the YLV(Y/I/M) sequence are IPMIs enzymes. |