Cooperative hemoglobins: conserved fold, diverse quaternary assemblies and allosteric mechanisms

Royer, William E.; Knapp, James E.; Strand, Kristen; Heaslet, H.

doi:10.1016/s0968-0004(01)01811-4

Cited by 106 publications

(105 citation statements)

References 43 publications

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“…Cooperativity and Allosteric Effects-In contrast to a remarkably conserved tetrameric arrangement in vertebrate hemoglobins, invertebrate hemoglobins show a large diversity in quaternary structures (36 (2, 3). Several mutant forms of the Hb I, Si dimer have structurally characterized, suggesting that two residues play an important allosteric role.…”

Section: Discussionmentioning

confidence: 99%

“…The distance between the iron atoms in the dimer is 17.8 Å, and the plane orientation of the porphyrin ring is almost perpendicular. This short distance between the heme groups is a characteristic feature of the EF-dimers in other types of molluscan hemoglobin (36). The dimer interface includes 25 residues of each monomer and covers a surface of 845 Å 2 .…”

Section: Hbii Lp Structure and Sequence Analysis-thementioning

confidence: 95%

See 1 more Smart Citation

Structure and Ligand Selection of Hemoglobin II from Lucina pectinata

Gavira

Cámara-Artigas

Jesús-Bonilla

et al. 2008

Journal of Biological Chemistry

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Section: Discussionmentioning

confidence: 99%

Section: Hbii Lp Structure and Sequence Analysis-thementioning

confidence: 95%

Structure and Ligand Selection of Hemoglobin II from Lucina pectinata

Gavira

Cámara-Artigas

Jesús-Bonilla

et al. 2008

Journal of Biological Chemistry

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“…In fact, the x-ray crystal structure of CYP3A4 with progesterone bound shows that there is a tight binding site peripheral to the active site that lies 17 Å from the heme [21] Cooperativity by indirect interaction (i.e. allosteric interaction) has been classically demonstrated in hemoglobin [58][59][60]. The idea of structurally distinct populations or conformational changes of CYP3A4 has been suggested previously [16,28,61].…”

Section: Discussionmentioning

confidence: 99%

Energetics of heterotropic cooperativity between α-naphthoflavone and testosterone binding to CYP3A4

Roberts¹,

Atkins²

2007

Archives of Biochemistry and Biophysics

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Cytochrome P450 3A4 (CYP3A4) is involved in the metabolism of a majority of drugs. Heterotropic cooperativity of drug binding to CYP3A4 was examined with the flavanoid, α-naphthoflavone (ANF) and the steroid, testosterone (TST). UV-vis and EPR spectroscopy of CYP3A4 show that ANF binding to CYP3A4 occurs with apparent negative cooperativity and that there are at least two binding sites: 1) a relatively tight spin-state insensitive binding site (CYP•ANF) and 2) a relatively low affinity spin-state sensitive binding site (CYP•ANF•ANF). Since binding to the spin-state insensitive binding site is considerably tighter for ANF than TST, the spin-state insensitive binding site could be occupied by ANF, while titrating TST at the other site(s).

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“…In hemoglobin, the T (unbound)-to-R (bound) transition occurs when one O 2 molecule binds to the heme group, causing a conformational change that displaces the F helix, inducing a shift of the intersubunit contacts that stabilize the high-affinity O 2 state (Turner et al 1992;Royer et al 2001). The binding of a ligand at one site that causes subsequent conformational changes that affect ligand binding at another site is a fundamental mechanism inclusive of other allosteric proteins (Copeland, 2000) and in the design of allosteric ribozymes (Koizumi et al 1999;Jose et al 2001).…”

Section: A Mechanism For Cooperative Glycine Bindingmentioning

confidence: 99%

Identification of a tertiary interaction important for cooperative ligand binding by the glycine riboswitch

Erion¹,

Strobel²

2010

RNA

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The glycine riboswitch has a tandem dual aptamer configuration, where each aptamer is a separate ligand-binding domain, but the aptamers function together to bind glycine cooperatively. We sought to understand the molecular basis of glycine riboswitch cooperativity by comparing sites of tertiary contacts in a series of cooperative and noncooperative glycine riboswitch mutants using hydroxyl radical footprinting, in-line probing, and native gel-shift studies. The results illustrate the importance of a direct or indirect interaction between the P3b hairpin of aptamer 2 and the P1 helix of aptamer 1 in cooperative glycine binding. Furthermore, our data support a model in which glycine binding is sequential; where the binding of glycine to the second aptamer allows tertiary interactions to be made that facilitate binding of a second glycine molecule to the first aptamer. These results provide insight into cooperative ligand binding in RNA macromolecules.

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Cooperative hemoglobins: conserved fold, diverse quaternary assemblies and allosteric mechanisms

Cited by 106 publications

References 43 publications

Structure and Ligand Selection of Hemoglobin II from Lucina pectinata

Structure and Ligand Selection of Hemoglobin II from Lucina pectinata

Energetics of heterotropic cooperativity between α-naphthoflavone and testosterone binding to CYP3A4

Identification of a tertiary interaction important for cooperative ligand binding by the glycine riboswitch

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