Hemes, Chlorophylls, and Related Compounds: Biosynthesis and Metabolic Regulation

Granick, S.; Beale, Samuel I.

doi:10.1002/9780470122914.ch2

Cited by 77 publications

(17 citation statements)

References 543 publications

(279 reference statements)

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“…This gene reveals 89.2% DNA sequence similarity to the corresponding hemB gene in S. aureus and 96% identity on the protein level (10). Heme is the prosthetic group of cytochromes, which play an essential role in electron transport (13). In this study, the S. epidermidis hemB mutant showed properties very similar to those of the SCVs recovered from clinical specimens and the S. aureus hemB mutant constructed previously (2,5,32,42,45), with tiny colonies growing at a slow rate.…”

Section: Discussionsupporting

confidence: 59%

Augmented Expression of Polysaccharide Intercellular Adhesin in a DefinedStaphylococcus epidermidisMutant with the Small-Colony-Variant Phenotype

et al. 2007

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While coagulase-negative staphylococci (CoNS), with their ability to form a thick, multilayered biofilm on foreign bodies, have been identified as the major cause of implant-associated infections, no data are available about biofilm formation by staphylococcal small-colony variants (SCVs). In the past years, a number of device-associated infections due to staphylococcal SCVs were described, among them, several pacemaker infections due to SCVs of CoNS auxotrophic to hemin. To test the characteristics of SCVs of CoNS, in particular, to study the ability of SCVs to form a biofilm on foreign bodies, we generated a stable mutant in electron transport by interrupting one of the hemin biosynthetic genes, hemB, in Staphylococcus epidermidis. In fact, this mutant displayed a stable SCV phenotype with tiny colonies showing strong adhesion to the agar surface. When the incubation time was extended to 48 h or a higher inoculum concentration was used, the mutant produced biofilm amounts on polystyrene similar to those produced by the parent strain. When grown under planktonic conditions, the mutant formed markedly larger cell clusters than the parental strain which were completely disintegrated by the specific ␤-1,6-hexosaminidase dispersin B but were resistant to trypsin treatment. In a dot blot assay, the mutant expressed larger amounts of polysaccharide intercellular adhesin (PIA) than the parent strain. In conclusion, interrupting a hemin biosynthetic gene in S. epidermidis resulted in an SCV phenotype. Markedly larger cell clusters and the ability of the hemB mutant to form a biofilm are related to the augmented expression of PIA.

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Section: Discussionsupporting

confidence: 59%

Augmented Expression of Polysaccharide Intercellular Adhesin in a DefinedStaphylococcus epidermidisMutant with the Small-Colony-Variant Phenotype

et al. 2007

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“…From the values of a/b ratio it can be deduced that chlorophyll b is more sensitive to viral infection than chlorophyll a. Reduced chlorophyll content has been reported in virus infected plants (Sinha and Srivatsava, 2010) and is attributed to stimulation of cell enzymes like chlorophyllase that degrades chlorophyll (Goodman et al, 1967), or it may be the effect of virus on pigment synthesis (Porter, 1959;Sadasivan, 1963;Granick and Beale, 1983;Balachandran et al, 1997) Chlorophyll b and (c) Total chlorophyll of healthy and infected Virupakshi (HB) and Grand Nain (GN) plants (Fraser, 1987). Other reasons for the decrease in chlorophyll content following virus infection may be accumulation of carbohydrates in the leaves (Watson, 1955).…”

Section: Resultsmentioning

confidence: 99%

Biochemical Characterization of Compatible Plant Virus Interaction: A Case Study with Bunchy Top Virus-Banana Host-Pathosystem

Anuradha¹,

Selvarajan²,

Vasantha³

et al. 2015

Plant Pathology J.

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A B S T R A C TVirus infection can result in the alteration of physiological, biochemical and metabolic processes within plants leading to symptom development. Banana bunchy top virus (BBTV) is one of the most destructive viral diseases in Tropical Asia, Pacific Indian Oceania (PIO) regions and Africa leading to 100% yield loss in banana and plantains. Though molecular characterization and their diversity were studied in depth in recent years, information on physiological and biochemical changes during banana-BBTV interaction is still not convincingly explained. Therefore, the present investigation was conducted to find out the quantifiable changes in physiological and biochemical parameters such as proteins, pigment and carbohydrate content, phenolic compounds, polyphenol oxidase (PPO), peroxidase (POX), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) activities in leaves of banana cultivars Grand Nain (AAA) and Virupakshi (AAB). The amount of carbohydrate contents, phenolic compounds, PPO, POX, APX, GPX, CAT were significantly higher in BBTV infected leaves of both the cultivars over the healthy, whereas total protein content, pigments and SOD activity showed an opposite trend. Overall the results suggest that BBTV infection induces significant changes in enzyme levels leading to irreversible symptom development. Further studies would lead to identification of biochemical markers for studying plant-virus compatible and incompatible interactions.

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“…Heme, an iron-containing tetrapyrrole, is vital for the survival and propagation of all living cells. In its role as a prosthetic group for hemoglobin, heme is involved in the binding and transport of oxygen (1,2). Other basic cellular processes that involve heme include electron transfers during respiration and the complex redox reactions catalyzed by cytochrome P-450 (2).…”

mentioning

confidence: 99%

“…In its role as a prosthetic group for hemoglobin, heme is involved in the binding and transport of oxygen (1,2). Other basic cellular processes that involve heme include electron transfers during respiration and the complex redox reactions catalyzed by cytochrome P-450 (2). Heme biosynthesis in mammals is accomplished by the sequential action of 8 enzymes (3)(4)(5)(6)(7).…”

mentioning

confidence: 99%

Structural insight into acute intermittent porphyria

Song

Cheng

et al. 2008

FASEB j.

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Acute intermittent porphyria (AIP), an inherited disease of heme biosynthesis, is one of the most common types of porphyria. Reduced activity of the enzyme porphobilinogen deaminase (PBGD), which catalyzes the sequential condensation of 4 molecules of porphobilinogen to yield preuroporphyrinogen, has been linked to the symptoms of AIP. We have determined the 3-dimensional structure of human PBGD at 2.2 A resolution. Analysis of the structure revealed a dipyrromethane cofactor molecule covalently linked to C261, sitting in a positively charged cleft region. In addition to the critical catalytic D99, a number of other residues are seen hydrogen bonded to the cofactor and play a role in catalysis. Sequential entry of 4 pyrrole molecules into the active site is accomplished by movement of the domains around the hinges. H120P mutation resulted in an inactive enzyme, supporting the role of H120 as a hinge residue. Interestingly, some of the mutations of the human PBGD documented in patients suffering from AIP are located far away from the active site. The structure provides insights into the mechanism of action of PBGD at the molecular level and could aid the development of potential drugs for the up-regulation of PBGD activity in AIP.

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Hemes, Chlorophylls, and Related Compounds: Biosynthesis and Metabolic Regulation

Cited by 77 publications

References 543 publications

Augmented Expression of Polysaccharide Intercellular Adhesin in a DefinedStaphylococcus epidermidisMutant with the Small-Colony-Variant Phenotype

Augmented Expression of Polysaccharide Intercellular Adhesin in a DefinedStaphylococcus epidermidisMutant with the Small-Colony-Variant Phenotype

Biochemical Characterization of Compatible Plant Virus Interaction: A Case Study with Bunchy Top Virus-Banana Host-Pathosystem

Structural insight into acute intermittent porphyria

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