CCLVIII.—The relative reactivity of methylene groups in 1 : 3-diketones

Lovett, Arthur Bertram Edmund; Roberts, Elwyn

doi:10.1039/jr9280001975

Cited by 13 publications

(7 citation statements)

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“…The formation of similar DNA-protein complexes has been demonstrated for virus, phage and plasmid relaxation complex (Blair and Helinski, 1975;Lovett and Helinski, 1975;Rekosh et al, 1977;Yehle, 1978). In all cases the Fig.…”

Section: Discussionmentioning

confidence: 57%

VirD proteins of Agrobacterium tumefaciens are required for the formation of a covalent DNA-protein complex at the 5′ terminus of T-strand molecules.

Herrera-Estrella¹,

Chen²,

Montagu³

et al. 1988

The EMBO Journal

128

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The T‐DNA transfer process of Agrobacterium tumefaciens is activated by the induction of the Ti plasmid virulence (vir) loci by plant signal molecules such as acetosyringone. Upon initiation of the T‐DNA transfer process, site‐specific nicks occur at the 25‐bp border sequences. This cleavage leads to the generation of a free, linear ssT‐DNA molecule which is bound by sequence non‐specific VirE proteins. Here we present evidence for the involvement of other acetosyringone‐induced proteins in the formation of a covalent complex between the T‐strand and protein, designated the T‐complex. Alkaline gel‐electrophoretic analysis showed that proteins specifically bind to the 5′ termini of nicked T‐DNA molecules. The T‐complex can be formed in Escherichia coli when the VirD1 and VirD2 proteins are expressed.

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Section: Discussionmentioning

confidence: 57%

VirD proteins of Agrobacterium tumefaciens are required for the formation of a covalent DNA-protein complex at the 5′ terminus of T-strand molecules.

Herrera-Estrella¹,

Chen²,

Montagu³

et al. 1988

The EMBO Journal

128

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“…In contrast, E. coli SSB protein reduces the ATPase activity of P. mirabilis RecA protein by about 80%, which suggests that P. mirabilis RecA protein can only partially resist displacement by SSB protein from ssDNA. RecA protein has both DNA strand-exchange and E. coli LexA protein cleavage activities(122). The behavior of P. mirabilis SSB protein in these reactions is untested.Bacillus subtilis RecA (RecE) ProteinThe B. subtilis RecA (RecE) protein (Mr 38,300) , which displays 60% identity with the E. coli protein(120), is encoded by the gene previously known as recE(21).…”

mentioning

confidence: 99%

Homologous Pairing and Dna Strand-Exchange Proteins

Kowalczykowski¹,

Eggleston²

1994

Annu. Rev. Biochem.

325

221

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“…108.5-109. p. 70.6-72.l0, as a darker powder. There was, therefore, little evidence of fractionatio~l, supporting the correctness of our melting point, which was much higher than those recorded before, viz., 56" (53), 58-60" (52), and 62-63" (45).…”

Section: Attempted Resolution Of 7-(4'-carbon-y-2'-iodop/zenoxy)metammentioning

confidence: 99%

Hindered Diphenyl Ethers Related to the Bisbenzylisoquinoline Alkaloids

Allen¹,

Moir²

1963

Can. J. Chem.

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Sixteen steps from vanillin led to syntheses of ( a ) dimethyl 3-(4'-carbornethoxyphenoxy)-4,5-dimethoxyphthalate ( I c ) , a known degradation product of isochondrodendrine, and (b) the more hindered dimethyl 3-(4'-carbomethoxy-2'-methoxyphenoxp)-4,5-dimethoxyphthalate ( I a ) , which has not been derived from any alkaloid, though the usual concepts of biosynthesis do not rule out the occurrence of alkaloids which could lead to it. Diphenyl ethers related to l a would be expected to show the effects of steric hindrance, but even with the most hindered member of the group, 7-(41-carboxy-21-iodophenoxy)metameconine ( V A e ) , no evidence for a n appreciable half-life of rotational isomers could be obtained. Attempts to make diphenyl ethers through the condensation of phenols with dicyclohexylcarbodiimide led to other products.Diphenyl ethers of type I are of interest both because of their relationship to the bisbeilzylisoquii~oline alkaloids, and because of their place in the study of steric effects in diphenyl ethers. For example, the ester Ia would be expected to arise froin the hypothetical alkaloid IIa in the same reactions that actually gave Ic as the degradation product of the dimethyl ether of isochondrode~ldrine (IIb) (I). Indeed, our whole study of diphenyl -ethers arose from the efforts of Dr. J . A. McRae and his students to forin the ester Ia, the same biosynthetic argument3 that had succeeded for the structure of isochondrodendrine leading them to suppose IIa to be a probable structure for the alkaloid cularine (2, 3). The synthesis of Ia proved unexpectedly difficult, and the challenge presented by the difficulty maintained our interest even when it became apparent many years ago that Ia was not in fact closely related to cularine (111) (3).The early efforts of Dr. RllcRae and his students t o synthesize Ia had several practical results. Prolonged attempts to use the Ullmann reaction directly led t o the independent discovery of the transinethylation side reaction (5-7). Attempts to use the phthalide group as a guarded source of carboxyl groups led to two lines of attack continued in the present work: a study of the place of steric hindrance in the synthesis of diphenyl ethers (5, 9, 10, 13), and an extensive development of the chemistry of metameconine (IVa) (5,(8)(9)(10)(11)(12). Oxidation of the metameconines yielded phthalic acids. One of these (9) was related to pellotine (14) and to capaurine (15, 16), and another (11), an essential link in determining the structure of the bisbenzylisoquinoline alkaloids bebeerine and tubocurarine (17, 18), was synthesized by methods which added greatly to the security of its proof of structure.

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CCLVIII.—The relative reactivity of methylene groups in 1 : 3-diketones

Cited by 13 publications

References 0 publications

VirD proteins of Agrobacterium tumefaciens are required for the formation of a covalent DNA-protein complex at the 5′ terminus of T-strand molecules.

VirD proteins of Agrobacterium tumefaciens are required for the formation of a covalent DNA-protein complex at the 5′ terminus of T-strand molecules.

Homologous Pairing and Dna Strand-Exchange Proteins

Hindered Diphenyl Ethers Related to the Bisbenzylisoquinoline Alkaloids

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