About 75% of the charged residues in proteins are members of ion pairs that are located mostly on the protein surface.

Despite the strong electrostatic attraction interactions contribute little to the stability of a native protein.

TLS Online TPP Program

#Id: 7898

#XL - Q Biochemistry

TLS Online TPP Program

#Id: 7899

#XL - Q Biochemistry

Only 22 tRNAs are required for mitochondrial protein synthesis. The normal codon–anticodon pairing rules are relaxed in mitochondria, so that many tRNA molecules recognize any one of the four nucleotides in the third (wobble) position, allowing four codons to be recognized by a single tRNA.

TLS Online TPP Program

#Id: 7900

#XL - Q Biochemistry

Leber’s hereditary optic neuropathy

caused by a missense mutation in the mtDNA gene

encoding subunit 4 of the NADH-CoQ reductase

TLS Online TPP Program

#Id: 7901

#XL - Q Biochemistry

Deletions in mtDNA cause another set of diseases:

Chronic progressive external ophthalmoplegia

Kearns–Sayre syndrome

TLS Online TPP Program

#Id: 7902

#XL - Q Biochemistry

Single mutation in the TΨCG loop of the mitochondrial lysine tRNA

“Ragged-red” muscle fibers & uncontrolled jerky movements

TLS Online TPP Program

#Id: 7903

#XL - Q Biochemistry

Mitochondrial fusion and fission are mediated by a set of GTPase enzymes:

Mitochondrial fusion -MFN1/2 & OPA1

Mitochondrial fission- DRP1