Biliprotein maturation: the chromophore attachment

Scheer, Hugo; Zhao, Kai‐Hong

doi:10.1111/j.1365-2958.2008.06160.x

Cited by 173 publications

(183 citation statements)

References 105 publications

Supporting

Mentioning

181

Contrasting

Unclassified

Order By: Relevance

“…Although spontaneous binding of phycobilins to the apo-PBPs can be observed, the lyases ensure the correct binding of the chromophore with regard to the specific attachment site and stereospecificity (24,44,45). As of 2014, only one eukaryotic lyase has been studied in detail.…”

Section: Resultsmentioning

confidence: 99%

“…PE545 Assembly in G. theta-The attachment of phycobilins to apo-PBPs is usually mediated by PBP lyases that in general have high attachment site specificity (24). Although cyanobacterial PBP lyases have been investigated for some time, those of cryptophytes are largely unexplored.…”

Section: Peb Biosynthesis In G Theta Adopted From Cyanobacteria-mentioning

confidence: 99%

“…Once synthesized, the phycobilin is bound by a specific PBP lyase, which then facilitates the ligation of the chromophore to a specific cysteine residue within the apo-PBP (22)(23)(24). PBP lyases are distinguishable in the clades of E/F-, S/U-, and T-type lyases, and some members of the E/F-type have an additional isomerase function (25)(26)(27).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Insights into the Biosynthesis and Assembly of Cryptophycean Phycobiliproteins

Overkamp

Gasper

Kock

et al. 2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Cryptophytes like Guillardia theta utilize soluble phycobiliproteins for light-harvesting. Results: Guillardia theta adopted phycoerythrobilin biosynthesis from cyanobacteria, and the phycobiliprotein lyase GtCPES provides structural requirements for transfer of this chromophore to a specific cysteine residue of the apophycobiliprotein. Conclusion: Phycobiliprotein synthesis in Guillardia theta combines proven and novel components. Significance: Results provide a better understanding of the evolution and function of unusual phycobiliproteins in cryptophytes.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Peb Biosynthesis In G Theta Adopted From Cyanobacteria-mentioning

confidence: 99%

See 1 more Smart Citation

Insights into the Biosynthesis and Assembly of Cryptophycean Phycobiliproteins

Overkamp

Gasper

Kock

et al. 2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…Bilin strongly affects the conformation of the subunits, and contributes to the stability of the higher-order structure (Fischer and Scheer 1992;Toole et al 1998). Specific lyases are responsible for bilin attachment (Fairchild and Glazer 1994;Jung et al 1995;Scheer and Zhao 2008). Recently, lyases for PCB attachment to apo-APC subunits were identified and characterized in Synechococcus sp.…”

Section: Introductionmentioning

confidence: 99%

Biosynthesis of fluorescent cyanobacterial allophycocyanin trimer in Escherichia coli

Liu

Chen

et al. 2010

Photosynth Res

View full text Add to dashboard Cite

Allophycocyanin (APC), a cyanobacterial photosynthetic phycobiliprotein, functions in energy transfer as a light-harvesting protein. One of the prominent spectroscopic characteristics of APC is a strong red-shift in the absorption and emission maxima when monomers are assembled into a trimer. Previously, holo-APC a and b subunits (holo-ApcA and ApcB) were successfully synthesized in Escherichia coli. In this study, both holo-subunits from Synechocystis sp. PCC 6803 were co-expressed in E. coli, and found to self-assemble into trimers. The recombinant APC trimer was purified by metal affinity and size-exclusion chromatography, and had a native structure identical to native APC, as determined by characteristic spectroscopic measurements, fluorescence quantum yield, tryptic digestion analysis, and molecular weight measurements. Combined with results from a study in which only the monomer was formed, our results indicate that bilin synthesis and the subsequent attachment to apo-subunits are important for the successful assembly of APC trimers. This is the first study to report on the assembly of recombinant ApcA and ApcB into a trimer with native structure. Our study provides a promising method for producing better fluorescent tags, as well as a method to facilitate the genetic analysis of APC trimer assembly and biological function.

show abstract

“…The formation of chromophorylated phycobiliprotein was detected by the emission at 645 nm for PCB-containing chromoproteins (15), and at 575 nm for PEB-containing chromoproteins (13). Complete spectra in the 350 to 700 nm range were recorded to verify correct attachment and the absence of spontaneous addition products (6). Far-UV CD spectra were recorded at 20°C with a CD spectrometer (J-810, JASCO).…”

mentioning

confidence: 99%

Catalytic Mechanism of S-type Phycobiliprotein Lyase

Kupka¹,

Zhang

et al. 2009

Journal of Biological Chemistry

View full text Add to dashboard Cite

We now show that CpcS1 binds PCB and PEB rapidly with bi-exponential kinetics (38/119 and 12/8300 ms, respectively). Chromophore binding to the lyase is reversible and much faster than the spontaneous, but low fidelity chromophore addition to the apo-protein in the absence of the lyase. This indicates kinetic control by the enzyme, which then transfers the chromophore to the apo-protein in a slow (tens of minutes) but stereo-and regioselectively corrects the reaction. This mode of action is reminiscent of chaperones but does not require ATP. The amino acid residues Arg-18 and Arg-149 of the lyase are essential for chromophore attachment in vitro and in Escherichia coli, mutations of His-21, His-22, Trp-75, Trp-140, and Arg-147 result in reduced activity (<30% of wild type in vitro). Mutants R147Q and W69M were active but had reduced capacity for PCB binding; additionally, with W69M there was loss of fidelity in chromophore attachment. Imidazole is a noncompetitive inhibitor, supporting a bilin-binding function of histidine. Evidence was obtained that CpcS1 also catalyzes exchange of C-␤84-bound PCB in biliproteins by PEB.Phycobiliproteins are a homologous family of light-harvesting proteins present in cyanobacteria, red algae, and cryptophytes that absorb light in the spectral region between the chlorophyll absorption maxima at ϳ430 and ϳ680 nm: they contain linear tetrapyrroles (phycobilins) of which 1-4 are covalently attached to the subunits by thioether bonds to conserved cysteines (1-4). The chromophores are derived from heme by oxidative ring-opening and subsequent reduction (5) and then attached post-translationally. The correct attachment of most chromophores is catalyzed by lyases. Three phylogenetically unrelated types of lyases have been characterized in cyanobacteria (6). They are specific for certain binding sites and chromophores (7-16), but the reaction mechanisms are still unclear. A chaperone-like action has been proposed for E/Ftype lyases that catalyze chromophore attachment to Cys-84 of ␤-subunits of phyco(erythro)cyanins (17, 18). A more highly evolved function is suggested, however, by concomitant isomerizing reactions catalyzed by certain lyases (12,19,20), and by the finding that most lyases can bind the chromophore and then transfer it to the acceptor protein (15,21).Chromophore binding is particularly pronounced with the S-type lyases. CpcS1 from Nostoc PCC7120 6 rapidly forms an adduct with phycocyanobilin (PCB), 7 and the latter can be transferred in a much slower reaction to cysteine 84 of the ␤-subunits of phycocyanin (CpcB) or phycoerythrocyanin (PecB), suggesting that PCB-CpcS1 is an intermediate of the enzymatic reaction (21). Model reactions of PCB with nucleophiles resulted in the formation of addition products in which the chromophore is isomerized and which are also substrates for a CpcS1-catalzed chromophore transfer to the apo-proteins (20). We now report chromophore binding kinetics obtained by stopped-flow techniques, and identification of functional amino acid residues f...

show abstract

Biliprotein maturation: the chromophore attachment

Cited by 173 publications

References 105 publications

Insights into the Biosynthesis and Assembly of Cryptophycean Phycobiliproteins

Insights into the Biosynthesis and Assembly of Cryptophycean Phycobiliproteins

Biosynthesis of fluorescent cyanobacterial allophycocyanin trimer in Escherichia coli

Catalytic Mechanism of S-type Phycobiliprotein Lyase

Contact Info

Product

Resources

About