| Structural highlights
Function
HMOX1_ARATH Key enzyme in the synthesis of the chromophore of the phytochrome family of plant photoreceptors. Catalyzes the opening of the heme ring to form the open-chain tetrapyrrole biliverdin IX with the release of iron and carbon monoxide (CO). Produces specifically the biliverdin IX-alpha isomer. Can form complex with heme, is ferredoxin-dependent and its activity is increased in the presence of ascorbate. Plays a role in salt acclimation signaling. May affect the plastid-to-nucleus signaling pathway by perturbing tetrapyrrole synthesis. The plastid-to-nucleus signal plays an important role in the coordinated expression of both nuclear- and chloroplast-localized genes that encode photosynthesis-related proteins.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12]
Publication Abstract from PubMed
Arabidopsis thaliana heme oxygenase-1 (AtHO-1), a metabolic enzyme in the heme degradation pathway, serves as a prototype for study of the bilin-related functions in plants. Past biological analyses revealed that AtHO-1 requires ferredoxin-NADP(+) reductase (FNR) and ferredoxin for its enzymatic activity. Here, we characterized the binding and degradation of heme by AtHO-1, and found that ferredoxin is a dispensable component of the reducing system that provides electrons for heme oxidation. Furthermore, we reported the crystal structure of heme-bound AtHO-1, which demonstrates both conserved and previously undescribed features of plant heme oxygenases. Finally, the electron transfer pathway from FNR to AtHO-1 is suggested based on the known structural information.
Enzymological and structural characterization of Arabidopsis thaliana heme oxygenase-1.,Wang J, Li X, Chang JW, Ye T, Mao Y, Wang X, Liu L FEBS Open Bio. 2022 Sep;12(9):1677-1687. doi: 10.1002/2211-5463.13453. Epub 2022 , Jun 20. PMID:35689519[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Muramoto T, Kohchi T, Yokota A, Hwang I, Goodman HM. The Arabidopsis photomorphogenic mutant hy1 is deficient in phytochrome chromophore biosynthesis as a result of a mutation in a plastid heme oxygenase. Plant Cell. 1999 Mar;11(3):335-48. doi: 10.1105/tpc.11.3.335. PMID:10072395 doi:https://dx.doi.org/10.1105/tpc.11.3.335
- ↑ Davis SJ, Kurepa J, Vierstra RD. The Arabidopsis thaliana HY1 locus, required for phytochrome-chromophore biosynthesis, encodes a protein related to heme oxygenases. Proc Natl Acad Sci U S A. 1999 May 25;96(11):6541-6. doi: , 10.1073/pnas.96.11.6541. PMID:10339624 doi:https://dx.doi.org/10.1073/pnas.96.11.6541
- ↑ Vinti G, Hills A, Campbell S, Bowyer JR, Mochizuki N, Chory J, Lopez-Juez E. Interactions between hy1 and gun mutants of Arabidopsis, and their implications for plastid/nuclear signalling. Plant J. 2000 Dec;24(6):883-94. doi: 10.1046/j.1365-313x.2000.00936.x. PMID:11135121 doi:https://dx.doi.org/10.1046/j.1365-313x.2000.00936.x
- ↑ Mochizuki N, Brusslan JA, Larkin R, Nagatani A, Chory J. Arabidopsis genomes uncoupled 5 (GUN5) mutant reveals the involvement of Mg-chelatase H subunit in plastid-to-nucleus signal transduction. Proc Natl Acad Sci U S A. 2001 Feb 13;98(4):2053-8. PMID:11172074 doi:https://dx.doi.org/10.1073/pnas.98.4.2053
- ↑ Neff MM, Van Volkenburgh E. Light-Stimulated Cotyledon Expansion in Arabidopsis Seedlings (The Role of Phytochrome B). Plant Physiol. 1994 Mar;104(3):1027-1032. doi: 10.1104/pp.104.3.1027. PMID:12232145 doi:https://dx.doi.org/10.1104/pp.104.3.1027
- ↑ Parks BM, Quail PH. Phytochrome-Deficient hy1 and hy2 Long Hypocotyl Mutants of Arabidopsis Are Defective in Phytochrome Chromophore Biosynthesis. Plant Cell. 1991 Nov;3(11):1177-1186. doi: 10.1105/tpc.3.11.1177. PMID:12324588 doi:https://dx.doi.org/10.1105/tpc.3.11.1177
- ↑ Muramoto T, Tsurui N, Terry MJ, Yokota A, Kohchi T. Expression and biochemical properties of a ferredoxin-dependent heme oxygenase required for phytochrome chromophore synthesis. Plant Physiol. 2002 Dec;130(4):1958-66. doi: 10.1104/pp.008128. PMID:12481078 doi:https://dx.doi.org/10.1104/pp.008128
- ↑ Emborg TJ, Walker JM, Noh B, Vierstra RD. Multiple heme oxygenase family members contribute to the biosynthesis of the phytochrome chromophore in Arabidopsis. Plant Physiol. 2006 Mar;140(3):856-68. doi: 10.1104/pp.105.074211. Epub 2006 Jan , 20. PMID:16428602 doi:https://dx.doi.org/10.1104/pp.105.074211
- ↑ Gisk B, Yasui Y, Kohchi T, Frankenberg-Dinkel N. Characterization of the haem oxygenase protein family in Arabidopsis thaliana reveals a diversity of functions. Biochem J. 2010 Jan 15;425(2):425-34. doi: 10.1042/BJ20090775. PMID:19860740 doi:https://dx.doi.org/10.1042/BJ20090775
- ↑ Gisk B, Bregier F, Kruger RA, Broring M, Frankenberg-Dinkel N. Enzymatic ring opening of an iron corrole by plant-type heme oxygenases: unexpected substrate and protein selectivities. Biochemistry. 2010 Nov 30;49(47):10042-4. doi: 10.1021/bi1014369. Epub 2010 Nov , 3. PMID:20979354 doi:https://dx.doi.org/10.1021/bi1014369
- ↑ Xie YJ, Xu S, Han B, Wu MZ, Yuan XX, Han Y, Gu Q, Xu DK, Yang Q, Shen WB. Evidence of Arabidopsis salt acclimation induced by up-regulation of HY1 and the regulatory role of RbohD-derived reactive oxygen species synthesis. Plant J. 2011 Apr;66(2):280-92. doi: 10.1111/j.1365-313X.2011.04488.x. Epub 2011 , Feb 18. PMID:21205037 doi:https://dx.doi.org/10.1111/j.1365-313X.2011.04488.x
- ↑ Susek RE, Ausubel FM, Chory J. Signal transduction mutants of Arabidopsis uncouple nuclear CAB and RBCS gene expression from chloroplast development. Cell. 1993 Sep 10;74(5):787-99. doi: 10.1016/0092-8674(93)90459-4. PMID:7690685 doi:https://dx.doi.org/10.1016/0092-8674(93)90459-4
- ↑ Wang J, Li X, Chang JW, Ye T, Mao Y, Wang X, Liu L. Enzymological and structural characterization of Arabidopsis thaliana heme oxygenase-1. FEBS Open Bio. 2022 Sep;12(9):1677-1687. doi: 10.1002/2211-5463.13453. Epub 2022 , Jun 20. PMID:35689519 doi:https://dx.doi.org/10.1002/2211-5463.13453
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