classic paper-2010 for web_0

8/3/2019 Classic Paper-2010 for Web_0

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Classic papers in biochemistry

Structure at 2.8 resolution of F1-ATPase frombovine heart mitochondria

Nature, 370, 1994, 621-628

Abrahams, Leslie, Lutter & Walker

Thursday, 2 December 2010


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Mitochondria and F-ATPase

1980-1994



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How is pmf coupled to ATP synthesis?

Direct (Mitchell, Williams)

Indirect (Boyer, others)



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2NADH H2

O

2NAD+

FADH

2

FAD 2 H

+

4 H+

4 H+

2 H

4 H+

4 H+

QQH

2

QQH

2

[O

]2

e

2e

2

e

2

e

2

e

3-4 H+

3-4 H+

ATP

ADP + Pi

Cyt c

HumanmtDNA

3 proteins

The thirteen proteins encoded in

mitochondrial DNA

7 proteins2 proteins

1 protein



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P-loop sequences in F1-ATPase



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P-loop sequences in F1-ATPase

consensus G X X X X G K T

169-1 G D R Q T G K T159-163 G G A G V G K T



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Paul Boyer



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ATP binding site ofTP



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The ATP synthase



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20 nm



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Generation of rotation



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The H+/ATP and Na+/ATP ratios

For the synthesis of each ATP, the -subunit rotatesthrough 120

12 c-subunits/ring

H+

/ATP = 4 10 c-subunits in S. cerevisiae H+/ATP = 3.3 14 c-subunits in chloroplasts H+/ATP = 4.7 11 c-subunits in Na

+

-motive F-ATPases

Na+

/ATP = 3.7

Estimates of H+/ATP are in the range 3-4



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The mammalian c-ring

The bioenergetic cost of making an ATP molecule

in mammalian mitochondria

Watt et al (2010) PNAS 107, 16823



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/O i i i i i


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P/O ratio in mammalian mitochondria

NADH 2e- to O2 =10 H+ pumped out

Succinate 2e- to O2 = 6 H+ pumped out

ADP/ATP exchange + Pi/H+

symport = 1 H+

in

ATP synthase H+/ATP = 8/3 = 2.7

ATP synthesis H+/ATP = 3.7

Moles ADP phosphorylated/2e- to O2 = P/O ratio

e- donor P/O calc P/O exp

NADH 10/3.7=2.7 2.5

Succinate 6/3.7=1.6 1.5



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Species known to have trimethyl-lysine-43

Man, cows, sheep, pigs, rabbit, mice, rats

Chickens

Flies (Diptera)

NB Yeast has K43, but not trimethylated



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17

Lindsay Baker, Mike Runswick, John Walker and John Rubinstein, unpublished work



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Lindsay Baker, Mike Runswick, John Walker and John Rubinstein, unpublished workThursday, 2 December 2010


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Unresolved issues

The a-c-ring interface

Understanding differences between F-ATPases(regulation, ring symmetries, peripheral stalks)

Reconciling structures and biophysics

classic paper-2010 for web_0

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