WASHINGTON — President Barack Obama is choosing an influential scientist who helped unravel the human genetic code — and is known for finding common ground between belief in God and science — to head the National Institutes of Health.

Obama called Dr. Francis Collins "one of the top scientists in the world" in announcing his nomination Wednesday.

"His groundbreaking work has changed the very ways we consider our health and examine disease," Obama said.

The NIH is the nation's premiere medical research agency, directing $29.5 billion to spur innovative science that leads to better health. Collins, an early gene-hunter, would come to the job not just with the scientific credentials, but with a reputation for translating the complexities of DNA into language everyday Americans can understand.

The folksy Collins led the Human Genome Project that, along with a competing private company, mapped the genetic code — or, as he famously called it, "the book of human life."

"It is humbling for me, and awe-inspiring, to realize that we have caught the first glimpse of our own instruction book, previously known only to God," he said at a 2000 White House ceremony marking release of the genome's first draft.

For that work, he was awarded the Presidential Medal of Freedom, the highest civilian award. But he may be more widely known for his 2007 best-selling book, "The Language of God: A Scientist Presents Evidence for Belief."

And this spring, Collins, 59, was named one of GQ Magazine's "Rock Stars of Science," posing in cool shades as part of a publicity campaign to bring celebrity to science.

John Porter, a former Republican congressman from Illinois who now chairs the health advocacy group Research!America, called Collins "a perfect choice."

"He knows the science and he is an outstanding leader," Porter said.

Collins promises to make the NIH's important work more understandable not only for patients but for lawmakers who hold the agency's purse strings, said American Heart Association President Dr. Clyde Yancey.

"The real advantage he brings is the ability to translate deep and complex science to the lay population ... in a meaningful way that allows it to be tangible and actionable," he said.