The odds of obtaining even one of these by chance is 2.0 x 10 -44 - Hooby
This is a distraction from the topic but let's get it out the way.
There are perhaps 20,000 different proteins in human cells. The average number of amino acids in these proteins is around 400 or so. That makes Cytochrome C a relatively small molecule at just 104 amino acids. Not one of evolution's biggest achievements.
Your challenge seems to be that evolution could never come up with any protein because 'chance'.
The answer to your question is to be found in chapter one of every basic textbook on evolution. It was the great discovery of Charles Darwin. EVOLUTION is NOT ABOUT CHANCE.
Life doesn't have to wait for its lottery numbers to come up - natural selection is a chance accumulator.
The crucial thing about a protein is its physical shape. Amino acids join together in random ways like oddly shaped magnets combining to make larger shapes with all sorts of bumps and crevices. Something that is approximately the correct shape will give its host an advantage.
The number of sequences that will produce something 'good enough' is orders of magnitude greater than the - astonishingly massive - number of sequences that result in the optimum version.
It arrives at its final form as a result of natural selection that favours any small improvement. After that, any future changes will be selected for if and only if they don't negatively affect the efficiency of its function.
Artificial Intelligence and engineering are using versions of natural selection to optimise design.